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1 THE STRUCTURE AND COMPOSITION OF RIPARIAN VEGETATION IN TRINIDAD: A BASELINE FOR CONSERVA TION AND RESTORATION By NATALIE BOODRAM A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLOR IDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2009
2 2009 Natalie Boodram
3 To my Mom
4 ACKNOWLEDGMENTS I would like to thank m y chair Daniel Za rin, and committee members Tom Crisman, Mary Alkins-Koo, Carrie Reinhardt and Jane Southworth for all their guidance, advice and encouragement. This study was carried out with substantial support from institutions and agencies in Trinidad. The Department of Life Sciences of the University of the West Indies (UWI) provided laboratory space, field assistance, equipment and ve hicles. The Curator and staff of the National Herbarium of Trinidad and Tobago (TRIN) assisted with plant identificat ion and nomenclature. The Department of Surveying and Land Informati on provided spatial data. The UWI Analytical Services Unit provided laboratory space, equipment and reagents for soil particle size analysis. Soil samples were also analyzed at the Centra l Experiment Station (CES) of the Ministry of Agriculture, Land and Marine Resources (MALMR ). CES also provided field vehicles and field support. In particular, I would like to th ank the following CES staff members: Seunarine Persad, Imran Ali, Sean Joseph, Peter Abraham and Mahadeo Singh. The Forestry Division of MALMR also provided field support; in particular, Sheldon Williams helped establish my field sites in south Trinidad. I am also grateful to my family and friends w ho assisted in the field or helped review and edit my work. In particular, thanks go out to my mom and Tea. This study was financially supported by an Organization of American States Fulbright Ecology grant, a Compton Fellowship, and a University of Fl orida, Institute of Food and Ag ricultural Sciences research assistantship.
5 TABLE OF CONTENTS page ACKNOWLEDGMENTS...............................................................................................................4LIST OF TABLES................................................................................................................. ..........8LIST OF FIGURES.......................................................................................................................10ABSTRACT...................................................................................................................................11 CHAP TER 1 INTRODUCTION..................................................................................................................132 RIPARIAN VEGETATION ALONG 12 RIVERS IN TRINIDAD ...................................... 18Introduction................................................................................................................... ..........18Methods..................................................................................................................................20Study Area.......................................................................................................................20River Selection................................................................................................................22Site Selection...................................................................................................................24Vegetation Data............................................................................................................... 25Environmental and Anthropogenic Data......................................................................... 26GIS and Map Data...........................................................................................................28Laboratory Analyses........................................................................................................ 28Data Analyses..................................................................................................................28Results.....................................................................................................................................29River Profiles...................................................................................................................30Caura........................................................................................................................30Arouca......................................................................................................................31North Oropouche......................................................................................................33Aripo.........................................................................................................................34Caparo......................................................................................................................36Couva.......................................................................................................................38Lebranche................................................................................................................39Cumuto..................................................................................................................... 40South Oropouche......................................................................................................43Moruga.....................................................................................................................44Poole.........................................................................................................................46Summary of Environmental and Anthropogeni c Characteristics of Riparian Zones...... 47Summary of Plant Comp osition and Structure................................................................ 48Importance value, species richness and diversity..................................................... 48Plant taxonomy.........................................................................................................49Discussion...............................................................................................................................50Anthropogenic Characteristics of Riparian Zones in Trinidad........................................ 50Environmental Characteristics of Riparian zones in Trinidad........................................ 53
6 Riparian Plant Composition and Vegetation Types in Trinidad ..................................... 54Riparian Vegetation Structure......................................................................................... 59Riparian Zone Delineation..............................................................................................60Summary..........................................................................................................................613 RIPARIAN VEGETATION GROUPS AN D DETERMINANTS IN TRI NIDAD............... 87Introduction................................................................................................................... ..........87Methods..................................................................................................................................90Data Collection and Scaling............................................................................................90Statistical Analyses.......................................................................................................... 91Vegetation groups.................................................................................................... 91Indicator species analysis......................................................................................... 92Environmental and anthropogenic determ inants of riparian vegetation.................. 92Results.....................................................................................................................................94Discussion...............................................................................................................................99Vegetation Groups........................................................................................................... 99Environmental and Anthropogenic Determ inants of Riparian Vegetation................... 100Variable Scales..............................................................................................................103Riparian Species in Trinidad......................................................................................... 104Conclusion.....................................................................................................................1054 A RIPARIAN CONSERVAT ION AND RESTORATION INDEX FOR TRINIDAD ...... 132Introduction................................................................................................................... ........132Human Impacts on Riparian Zones............................................................................... 132Riparian Restoration...................................................................................................... 133Riparian Indices............................................................................................................. 134Objectives......................................................................................................................136Methods................................................................................................................................137Literature Review.......................................................................................................... 137General Methodology....................................................................................................138Inventory, Classification and Establ ishment of Reference Conditions......................... 139Indicators..................................................................................................................... ..140Index Design and Validation.........................................................................................140Results...................................................................................................................................142Literature Review.......................................................................................................... 142Inventory, Classification a nd Vegetation Determinants................................................ 142Indicators..................................................................................................................... ..143Discussion.............................................................................................................................144Suitabliltiy of Metrics.................................................................................................... 144Index Design, Validation and Constraints.....................................................................147Tropical Island Context.................................................................................................148Restoration Techniques................................................................................................. 148River Management........................................................................................................150
7 5 CONCLUSIONS.................................................................................................................. 164Research Synthesis...............................................................................................................164Riparian Research Needs......................................................................................................165Riparian Management in Trinidad........................................................................................ 166River Management in Trinidad............................................................................................. 167APPENDIX A LIST OF SPECIES FOUND IN RIPARIAN ZONES IN TRINIDAD................................ 169B PHOTOGRAPHS OF THE LOWER MIDD LE AND UPPE R REACHES OF EACH RIVER STUDIED................................................................................................................ 185C SITE LEVEL ENVIRONMENTAL AND LAND USE DATA.......................................... 197D LAND USE, CANOPY CLOSURE, SLOP E AND CUM ULATIVE ELEVATION FOR EACH 10 X 10 M BLOCK.................................................................................................. 198E PHYSICAL AND CHEMICAL SOIL PAR AMETERS FOR EACH 10 X 10 M BLOCK.................................................................................................................................211F SPECIES FOUND AT ONLY ONE SITE ........................................................................... 219G ORDINAL VARIABLE RANKINGS AND JUSTIFICATIONS ....................................... 225H CRITERIA FOR RANKING RIPARI AN ZONE AND UPL AND EDAPHIC MODIFICATION.................................................................................................................230I SIGNIFICANT CORRELATIONS AMONG E NVIRONMENTAL AND ANTHROPOGENIC VARIABLES US ED IN BIOENV ANALYSES.............................. 232J RAPID RIPARIAN ZONE ASSESSMENT PROTOCOL FOR TRINIDAD..................... 234LIST OF REFERENCES.............................................................................................................237BIOGRAPHICAL SKETCH.......................................................................................................246
8 LIST OF TABLES Table page 2-1 Rivers used in the study................................................................................................... ..63 2-2 Environmental and anth ropogenic data collected ..............................................................64 2-3 Summary of block and site level m etric data.....................................................................65 2-4 Summary of site le vel categorical data ..............................................................................66 2-5 Catchment characteristics.................................................................................................. 68 2-7 Species with the 20 highest relative coverage va lues in the ground flora. ........................72 2-8 Diversity, species richness, most importan t tree species and highest percentage cover ground flora plant per site ..................................................................................................73 2-9 Catchment species richne ss (trees and ground flora) ......................................................... 75 2-10 Catchment species diversity (trees and ground flora)........................................................ 75 2-11 Richness and diversity by Geomorphol ogical Unit, Ecoregion and Level of catchm ent human impact................................................................................................... 75 2-12 Species found in this study, which are known to be associated with rivers or swam ps according to Adams & Baksh-Comeau (Unpublished)..................................................... 76 2-13 General vegetation classification of the sites used in the study according to Beard (1946) and Nelson (2004) .................................................................................................. 78 3-1 Scales of environmental and anthrop ogenic variables m easured in the study................. 107 3-2 Indicator species for vegetation group clusters of presence/absence data for 108 am algamated blocks......................................................................................................... 108 3-3 Indicator species for group clusters of ground flora for 108 amalgam ated blocks.......... 110 3-4 Indicator species for group clusters of trees for 84 am algamated blocks........................ 111 3-5 BIOENV and BVSTEP results........................................................................................ 112 3-6 Correlations between ground flora indicator species abundance and m etric and ordinal variables from the 1-6 BIOENV variable solutions............................................113 3-7 Correlations between tree indicator sp ecies abundance and metric and ordinal variables from the 1-6 BIOENV variable solutions .........................................................113
9 3-8 List of Riparian species for Trinidad............................................................................... 114 4-1 Examples of riparian assessment methodol ogies, applications, scoring and validation m ethods............................................................................................................................151 4-2 Most commonly used field indi cator variables from Table 4-1....................................... 156 4-3 Recommended site management stra tegies based on detailed taxonom ic and classification analyses...................................................................................................... 158 4-4 Index results for sites in the North G eomorphological Unit............................................ 159 4-5 Index results for sites in the South Geom orphological Unit............................................160
10 LIST OF FIGURES Figure page 2-1 Trinidad, Republic of Trinidad and Tobago...................................................................... 802-2 Geomorophological regions in Trinidad............................................................................ 812-3 Trinidad Ecoregion Classification.....................................................................................822-4 Rivers and watersheds...................................................................................................... ..832-5 Watershed forest cover..................................................................................................... .842-6 Site locations............................................................................................................. .........852-7 Location and dimensions of transects and quadrats at each site........................................ 863-1 Combined vegetation sample blocks, used in hierarchical cl uster analysis grouped according to distan ce from river...................................................................................... 1163-2 Dendrogram of hierarchical cluster analysis of presence/absence data for 108 amalgamated blocks......................................................................................................... 1173-3 Dendrogram of hierarchical cluster analysis of ground flora data for 108 amalgamated blocks......................................................................................................... 1183-4 Dendrogram of hierarchical cluster analys is of tree data for 84 amalgamated blocks....1193-5 NMDS ordination map of presence/absence block plant data......................................... 1204-1 Hierarchy of information of ecological information........................................................ 1614-2 Site management strategies base d on taxonomic and classification data........................ 1624-3 Indicator selection process...............................................................................................163
11 Abstract of Dissertation Pres ented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy THE STRUCTURE AND COMPOSITION OF RIPARIAN VEGETATION IN TRINIDAD: A BASELINE FOR CONSERVA TION AND RESTORATION By Natalie Boodram May 2009 Chair: Daniel Zarin Major: Interdisciplinary Ecology The structure and composition of riparian vegeta tion of 12 rivers in Trinidad were detailed, along with concurrent environmenta l and anthropogenic characterist ics of the riparian zone and associated watershed. Cluster analysis, non-metric multi-dimensional scaling, and Spearman rank correlations were used to delineate riparian vegetation groups and indicator species, identify the most significant determinants of riparian vegetation groups and determine the most influential scale of variables. These data we re used to develop a rapid assessment index to identify and prioritize riparian sites for conservation and restoration. An approximate riparian zone width of 30 m was suggested for Trinid ad and a list of 57 native riparian species generated. Of 36 randomly chosen sites, only nine were in forested areas. Fifteen were in abandoned agricultu ral estates. The others were in agricultural, grassland and developed areas. An exotic species, Bambusa vulgaris, had the highest tree importance value and another exotic, Coffea sp., had the highest ground flora coverage. Nine major vegetation groups were identified and named according to dominant species, distribution and major determinants. These are Justicia secunda-Eschweilera subglandulosa (North Forest), Mora excelsa-Bactris major (South Forest), Saccharum officinarum (Agricultural), Axonopus compressus (Agricultural), Justicia secunda (Secondary Vegetation),
12 Flemingia strobilifera (Fire Influenced), Sorghum sp (Weedy Species), Acroceras zizanioides (Native Grasses) and Bambusa vulgaris (Bamboo) groups. With the exception of canopy closure, form factor and geomorphology, the best predictors of riparian vegetation groups were anthropogenic variables like the degree of upland and riparian zone edaphic modification, fire, channel modification, distance from paved roads, land ownership and pollution. Out of a 4-level hierarchy of variables, Meso scale (reach leve l) variables were most important in explaining riparian vegetation patterns. The rapid riparian index, which was devel oped, used eight variables to identify and prioritize sites for restorati on and conservation. These incl uded tree species richness, presence/absence of easily recognizable exot ic and secondary vegetation species, and anthropogenic indicators like fire, channel m odification and anthropoge nic disturbance.
13 CHAPTER 1 INTRODUCTION Current ecological paradigm s emphasize in terconnectivity between ecosystems and processes and patterns across both multiple scales and ecological gradients (Wiens 2002). Scales, gradients and interconnectivity ar e also factored into curren t natural resource management practices and ecosystem restorat ion strategies (Wissmar & Besc hta 1998). These paradigms and management strategies are appl icable to all terrestrial and aquatic ecosystems and are also relevant to terrestrial-aquatic inte rfaces such as riparian zones. Riparian zones are transitional areas between terrestrial and freshwater systems. They include riverbanks and shores of ponds and lake s. Along riverbanks, riparian zones extend from the waters edge to the areas la ndward that either experience floodi ng or have elevated soil water levels. The importance of riparian zones lies in the fact that they connect aquatic and terrestrial ecosystems and also shape and influence them (Naiman et al. 2005). Riparian zones influence terrestrial systems vi a nutrient inputs, for example, when animals feed in riparian areas and re lease waste material upland (N aiman & Rogers 1997). Riparian zones also influence aquatic systems by inte rcepting surface runoff and groundwater, which drain into rivers and ponds. Ripari an plants absorb nutrients and po llutants, trap sediment and in so doing, buffer river water quality. Improved water quality benefits not only aquatic wildlife, but also humans using the site for recreati on and water extraction (Peterjohn & Correll 1984; Darby 1999). In trapping and retaining sediment, ri parian plants also stre ngthen riverbanks and reduce erosion (Anbumozhi et al. 2005). Riparian vegetation can provide food for aquatic fauna by contributing woody debris and other organic material to th e river. Woody debris creates aquatic habitat by trapping sediment, reducing current velocity and forming pools (Darby 1999).
14 While riparian zones influence adjacent system s, their characteristic s are also affected by adjacent terrestrial and a quatic systems. Riparian biotic com position, soil texture, soil nutrients, and spatial characteristics can vary, depending on river hydrological re gime and terrestrial geomorphology. In particular, rive r channel depth, velocity and flooding regime can greatly impact riparian zones. Flooding facilitates ripari an plant dispersal and re plenishes soil nutrients (Naiman & Decamps 1997). Geomorphological factor s include fine scale factors like channel slope and broader scale asp ects like watershed size and sh ape. Geomorphology and hydrology often act in tandem; for instance, riparian zones on shallow riverbank gradients are more prone to flooding. Biological processes such as plant co mpetition, herbivory and succession also shape riparian characteristics (Tabacchi et al. 1998). In recent times, humans have started to ex ert greater influence on riparian zones via vegetation removal or alterati on of hydrological regimes thro ugh dam construction or dredging. Such impacts on riparian areas can also be on a much broader scale, for example, through land use changes in the watershed that can change the volume, timing and chemical composition of water filtering through riparian zones (Nationa l Research Council 2002). At an even broader scale, riparian vegetation is controlled by regional cl imate (Lite et al. 2005). Riparian zones are not only shaped by their lateral connections to adjacent ecosystems but also longitudinal connec tions and gradients. Riparian st ructure and function can change in response to downstream gradient s in riverbank soil particle size (Mitsch & Gosselink 1993). Ecological gradients are also seen on a smaller sc ale, for example, a change in vegetation within the riparian zone due to decrea sing moisture levels farther away from the river (Turner et al. 2004).
15 Riparian areas are important ecosystems in their own right. They are complex, dynamic systems with great heterogeneity and accompanying high levels of plant productivity and diversity (National Research Council 2002). Riparian zones are also important habitats and corridors for the movement of animals (Gregory et al. 1991). Given th e important roles of riparian zones, there has been much em phasis on their management, conservation and restoration. Restoration is especially important as riparian areas are subject to high levels of human interference through settlement, agricult ure, transportation a nd recreation (National Research Council 2002). To improve management, conservation and restora tion, there must be a detailed understanding of riparian systems in cluding the composition and structure of the vegetation and its determinants. Protection of ri parian ecosystems in turn is critical for management of adjoining aquatic systems (Allan et al. 1997). Past research has focused on hydrological a nd broad scale geomorphol ogical controls of riparian vegetation. There has been less research on human influences on riparian vegetation and few interdisciplinary studies that incorporate the influence of both eco logical and anthropogenic factors. Multiple scale studies are also lack ing. While there is substantial information on temperate riparian systems and large tropical ri vers, there are less data on riparian vegetation along narrow, short rivers found on tropical island s. In the Caribbean, there has been some riparian vegetation research in Puerto Rico. Hear tsill-Scalley & Aide (200 3) examined variations in vegetation composition and structure under vary ing land use conditions. However, the Puerto Rican literature has focused more on leaf litte r decay and nutrient exchange between rivers and the riparian zone (Lodge et al. 1991; O'Connor et al. 2000) rather than analyses of composition and species distribution.
16 The overall goal of this study is to examine th e structure, composition and determinants of riparian vegetation in Trinidad to provide a ba seline for conservation and restoration of the islands riparian ecosystems. Trinidad, Republic of Trinidad and Tobago, is a Caribbean island just north of Venezuela. It is rich in biodiversity and natural resources, but is experiencing high levels of industrialization and environmental de gradation due to its oil based economy (Water Resources Agency 2001). This study contributes to water resources and aquatic ecosystems management research in Trinidad carried out by th e Life Sciences Department at the University of the West Indies (UWI). It provides ripari an data that, in conjunction with ongoing water quality, aquatic ecology and land use studies, can form the basis for river management on the island. Additionally, this study wi ll contribute to the limited in formation on riparian zones on the small, tropical islands of the Caribbean. This study is divided into thr ee main chapters. The following ch apter (Chapter 2) describes vegetation and environmental conditions at 36 site s, along 12 rivers in Trinidad. An account of anthropogenic influences along the ri vers is also provided as well as selected characteristics of the associated watershed. The field surv ey methodology is described and vegetation is characterized in terms of re lative frequency, density, coverage, importance value, species richness and diversity. Comparisons are made to existing riparian vegetation literature from nearby countries, and there is a discussion of the vegetation with in the context of the general flora of Trinidad. The aim of Chapter 3 is to determine the re lative importance of multi-scale hydrological, terrestrial (abiotic) and human influences on ri parian vegetation compos ition and structure in Trinidad. Sites are grouped based on vegetation characteristics using cl uster analysis and non-
17 metric multi-dimensional scaling. Indicator spec ies for each group are delineated and the most significant variables controlling the distribution of the vegetation groups are determined. Chapter 4 utilizes information from Chapters 2 & 3 to develop and test an index to assess the biological integrity of riparian sites. The index also identifies a nd prioritizes potential riparian conservation and restoration sites. Chapter 5 summarizes the study results and prov ides recommendations for future research. It also provides suggestions as to how this st udy can be integrated into environment management strategies in Trinidad.
18 CHAPTER 2 RIPARIAN VEGETATION ALONG 12 RIVE RS IN TRINIDAD Introduction Riparian zo nes are found along banks of rivers and streams and are transition areas or ecotones between terrestrial and aquatic environm ents. They also influence the structure and functioning of adjacent ecosystems (Naiman et al. 2000). Riparian zones have high plant productivity due in part to high temperatures light and moisture along riverbanks. High productivity is also linked to flooding along ri vers (Tabacchi et al. 1998; Naiman et al. 2000). The flood pulse theory (Junk et al. 1989) refers to the lateral ex change between a river and its floodplain and the accompanying adaptations of the floodplain biota. The fl ood pulse results in a higher productivity level for both aq uatic and riparian systems, as it facilitates nutrient exchange and waste product removal. Riparian systems also have high biotic diversity due to the wide variety of ecological niches associated with phys ical heterogeneity and h eavy disturbance caused by flooding and river channel migration (Gregory et al. 1991; Naiman et al. 2000). Riparian plants are tolerant of the hars h, dynamic conditions along riverbanks. They are adapted to flooding, shear stress due to high river velocity, and dry conditions during low river discharge. During periods of flooding, riparian soils can become anoxi c, thus adaptations such as adventitious roots and aerenchyma root cells are common in riparian plant species. Plant zonation is also common, often in response to water table and floodi ng gradients (Naiman & Decamps 1997). Riparian zones also have a high abundance of exotic plant species due to their ability to adapt to harsh dyna mic conditions and rapidly disp erse along riparian corridors (Richardson et al. 2007). Riparian vegetation provides food and habitat fo r terrestrial fauna. The plants also provide food, substrate and habitat for aquatic species when leaves, flowers, fruits and woody debris fall
19 into steams. Riparian plants can influence the form and function of adja cent water bodies; for example, overhanging vegetation can reduce water temperature (Nagasaka & Nakamura 1999), and river discharge can be lowered through ripari an plant evapotranspiration. Riparian zones also buffer the water quality of the adjacent river. This takes place when riparian plants trap sediment and pollutants and take up nutrients from surface and groundwater filtering into the stream. Riparian plant buffers are often created or maintained for water quality protection especially at sites used for recreation a nd water abstraction (Naiman & Decamps 1997). Past riparian research has largely been carried out in temperate areas or along large tropical continental rivers. Baseline riparian invent ories have been conducte d throughout Europe, North America and South America, for example, Higler (1993), Nebel et al. (2001) and Holmes et al. (2004). Studies on riparian vegetation determinants have also been focused in these geographic areas, for example, Turner et al. (2004) worki ng in Wisconsin and Sheridan & Spies (2005) in Oregon. Practical applications of riparian research have been de vised by Bentrup (2004) working in Kansas to find appropriate si tes for riparian buffers or Pete rjohn & Correll (1984) who studied the ability of riparian buffers to ab sorb soil nitrates in Maryland. Riparian ecological concepts ha ve also been derived from tr opical continental or temperate research. For example, Junk et al (1989) developed the flood pulse theory in part by observing flooding along the Amazon River. Johnson & Lowe (1985) based their intr a-riparian continuum concept on research conducted in the United States. This concept described variations in the spatial extent of the riparian community moving downstream due to changing geomorphology. Mitsch & Gosselink (1993) described a downstream change in riparian ecosystem structure and function in response to a downstream gradient in stream bank soil particle size, based on studies in Oregon and along the Mississippi River in the United States.
20 Tropical island riparian research is lacking in all aforemen tioned areas. Basic vegetation inventories are needed as well as data on envi ronmental properties and anthropogenic influences on riparian vegetation. Riparian bu ffer research is lacking; hence, the water quality benefits of riparian zones are not fully exploited on tropical islands. Finally, the applicability of general riparian ecological concepts to the short narrow rivers of tropi cal islands is not known. In the Caribbean there has been limited riparian research in Puerto Rico, for example, Heartsill-Scalley & Aide (2003) who examined variations in vegetation composition and structure under varying land use conditions, and Lodge et al. (1991) who st udied leaf litter decay and nutrient exchange in the riparian zone. However, research is lacki ng in other Caribbean island s, including Trinidad. The goal of this chapter is to describe the structure and composition of riparian vegetation along 12 rivers in Trinidad. Apart from an account of the riparian plants, hydrological properties of the corresponding rivers ar e detailed as well as envi ronmental and anthropogenic characteristics of the riparian zones. Selected properties of the associated watershed are also highlighted. This chapter provides baseline ripa rian vegetation, environmental and anthropogenic data for Trinidad. In turn, results can be us ed to study riparian vegetation determinants, incorporated into riparian water quality buffer research, used to inform conservation and restoration, and used to test and bu ild on riparian ecological theories. Methods Study Area Trinidad is the larg er island of the Republic of Trinidad and Tobago (Figure 2-1). It is located between 10 2' and 11 2' N latitude and 60 30' and 61 50' W longitude, just off the coast of Venezuela (Berridge 1981) Trinidad is a 4826 km2 continental island, sharing a similar geological profile and natural history with nei ghboring South American countries (Beard 1946). There are three mountain ranges on the island, namely the Northern, Central and Southern
21 Ranges. The highest point, Cerro del Aripo, is in the Northern Range at an elevation of 900 m. The Caroni Plain separates the Northern and Ce ntral Ranges, and the Naparima Plain separates the Central and Southern Ranges (Water Res ources Agency 2001; Day & Chenoweth 2004) as seen in Figure 2-2. Ninety-nine percent of the island is made up of sedimentary and metamorphic rocks (Water Resources Agency 2001) Trinidad has a seasonal, tropical climate. Th e dry season is from January to May and the rainy season from June to December. Total annua l rainfall ranges from 3048 mm in the northeast of the island to 1524 mm in the northwest, s outhwest and small offshore islets. Mean annual temperature is 25 C ( Water Resources Agency 2001; Day & Chenoweth 2004) The Water Resources Agency (2001) has desi gnated 54 watersheds on the island. The major river systems are the Caroni, North Oropouc he, South Oropouche, Navet and Ortoire. The Caroni River is the widest (30 m), and the Ortoir e River is the deepest at 6 m (Phillip 1998). The mean width for 114 rivers sampled in Trinidad (Phillip 1998) was 5.96 m, and the mean depth was 0.49 m. The total population of Trinidad and Tobago is approximately 1.25 million; however, only 4% of the people live in Tobago (Water Resour ces Agency 2001). In 1980, 45% of Trinidad was covered in forest decreasing to 34% in 1990 due to agriculture, housing and industry. However, given the countrys current heavy rate of industrialization, much of the agricultural land has been abandoned and is experiencing secondary growth. Th is has resulted in increased forest cover of 60% in 2000 (Gibbes 2006). Beard (1946) divided the islands vegetation in to four climatic vegetation formations: the Seasonal, Dry Evergreen, Montane and Intermedia te formations. He also designated Swamp and Marsh Edaphic formations. Each formation was further divided into groups of common structure
22 and lifeforms called associations. Most of the islands vegeta tion falls under the Seasonal formation. The most widespread floristic a ssociation is the Evergreen Seasonal Forest association dominated by Carapa guianensis Aubl. (Crappo) and Eschweilera subglandulosa (Steud.) locally know n as Guatecare. Nelson (2004) also classified the vegetation of Trinidad and develope d a hierarchical threetier classification framework for the island. The first, the Ecoregion tie r, roughly halved the island along a north-south axis based on potential evapotranspiration. The eastern half of the island was designated the Moist Forest Ecoregio n and the western part was the Dry Forest Ecoregion (Figure 2-3). The two Ec oregions were then divided into nine lifezone tiers, and each was further divided into 13 landscape units. Nelsons (2004) landscape units approximate Beards floristic association categories. Neither Beard (1946) nor Nelson (2004) provided in-depth information on riparian vegetation in Trinidad. Beard (1946) wrote a su bstantial discussion of wetland floristic data, focusing on the Nariva freshwater swamp, a RAMSAR site in the eastern part of the island (Brown 2000). In terms of ripa rian vegetation; however, Beard (1946) only noted the presence of Pterocarpus officinalis Jacq. (Swamp Bloodwood) in sta nds at the mouth of the North Oropouche River. River Selection Twelve rivers were selected across Trinidad for study. Ri vers and their associated catchm ents were delineated from a Geographic Information Systems (GIS) catchment layers obtained from the Department of Surveying and Land Information of the University of the West Indies (Figure 2-4). Past ri parian studies have pointed to the importance of climate, geomorphology, and human activities in shaping stru cture and composition of riparian vegetation (Tabacchi et al. 1998; Turner et al. 2004; Williams & Wiser 2004; Lite et al. 2005). Hence, for
23 this study in Trinidad, the 12 ri vers were chosen to reflect rainfall conditions, geomorphology and level of human impact across the island. Rainfall levels were represented by the Ecoreg ion Classification of Nelson (2004) as seen in Figure 2-3 that roughly halved the island along a north-south axis based on a potential evapotranspiration ratio of 0.75. Six catchments were chosen from the western Dry Ecoregion area and six from the eastern Wet Ecoregion (F igure 2-3). Catchments were further divided based on geomorphology, four were in the Northern Range (North Unit), four in the Caroni Plain/Central Range (Central Unit) and four in the Naparima Pl ain/Southern Range (South Unit) as seen in Figure 2-2. The third criterion for catchment selection wa s level of human impact. Forest cover was used as a proxy for this parameter, where catchme nts with high forest cover were used as low human impact sites. Forest cover was initially delineated using a 1994 land use GIS layer with 50 land use categories, based on 1994 aerial photogra phs. Forest cover was calculated as the sum of the area of the following land use categories: 1. Forest 2. Scrub-Fire Burnt or Permanently Dwarfed Vegetation 3. Mangrove 4. Swamp, 5. Swam p and Forest and finally 6. Swamp Forest. Teak and Pine plantations were not included as forest, as timber plantations have a high level of human impact. Similarly, categories such as Brok en Forest were not included as they implied human intervention. While the category Scrub-Fi re Burnt or Permanently Dwarfed Vegetation suggests human interference, it was the only cate gory that encompassed dry forest vegetation in Trinidad and was thus, included as a Forest category. Forest cove r in each watershed in Trinidad is shown in Figure 2-5. Delineation between high and low human impact was based on a minimum of 40% forest cover in watersheds on the western half of the island. This cut off point was chosen to factor in high levels of human impact due to agriculture industry and housing on
24 the west of the island. By contrast, on the eastern part of the island, the cut off forest cover level was 60%, as this side of the island has great er forest cover (Table 2-1 & Figure 2-5). Once all other criteria were met, adjacent wate rsheds were selected to ensure similar rainfall conditions. For the Northern Range site s, watersheds were onl y selected from southfacing slopes. While the Caparo watershed st raddled both the Dry and Wet Ecoregions, it was used, as it was the only site in the western part of the island that had a relatively high forest cover of over 40%. Sites were plotted alon g tributaries that fell within the Dry Ecoregion portion of the watershed. Similarly, for the Poole watershed in the Wet Ecoregion, a portion of the watershed fell within the Dry Ecoregion and, as a resu lt, tributaries from only the Wet Ecoregion component were used. The 1994 land use map was used as the primar y data source for watershed selection; however, a land use map developed by the Department of Surveying and Land Information at UWI based on 2001 Landsat images was used to corroborate forest cover levels (Chinchamee Unpublished Thesis). The high human impact catchments selected had lower levels of forest cover in both 1994 and 2001 (Table 2-1). Gibbes ( 2006) was not used to se lect watersheds, as data were not yet available during the site selection phase of this study. Where the watershed consisted of a number of sub-watersheds, the longest river within the watershed was chosen. River length was based on the distance from the m outh of the river to the headwaters of the longest tributary. Site Selection Sites were s elected to represent an upper, mid and lower reach point along each of the twelve rivers used in the study. The lower reach was selected as 10-30 % of river length from the river mouth, 40-60% of the length was designated the mid reach area, and 70-90% was considered the upper reach area. The lower r each segment was at leas t 1 km inland from the
25 coastline to avoid tidal influence. Within each re ach, five randomly chosen points were selected along the river. These were investigated for suitab ility and discarded if there were accessibility or safety issues. In summation, three sites were selected per river for a total of 36 sites across the 12 catchments (Figure 2-6). Sites were sel ected during 2006 and relocated in 2007 using GPS navigation. Vegetation Data Vegetation was surveyed between January a nd May of 2007 during the dry season to take advantage o f accessibility afforded by low river discharge levels. Trees and ground flora were surveyed on one randomly chosen bank of each of the sites selected. Data were collected along three; 50 m transects running perpendicular to the river channel and spaced 50 m apart (Figure 27). A total of 108 transects were established. Three of th e 108 transects were sp aced more or less than 50 m apart to avoid steep slopes, tributaries or dense patches of t horny vegetation. In the case of the Caparo Lower Reach site (CAPL) all three transects were relocated 200 m downstream to avoid an active dredging operation during the time of sampling. Steep slopes at the North Oropouche Upper Reach Site (NORU) ha mpered access to the site; hence, the point was moved to an accessible location approximately 1 km upstream. Each transect was divided into five contiguous 10 x 10 m blocks. All transects began at the waters edge and in the case of dry river cha nnels, at the base of th e riverbank. Block 1 was located closest to the river, and block 5 was at the end of the transect. The species and Diameter at Breast Height (DBH) of each tree (DBH> 10 cm) in each block was recorded. Plant samples were taken for identification and to serve as voucher specimens at the National Herbarium of Trinidad and Tobago (TRIN). In the case of mu ltiple trunks, where the trunk forked below the DBH level, each trunk was measured and total DB H recorded. DBH was estimated where trunks could not be measured using DBH tape, for exampl e, if they projected over the river channel.
26 For species such as Bambusa vulgaris L. (Bamboo) with numerous culms, the DBH of one representative culm was taken, and the number of culms in the bamboo stand was estimated to provide total DBH for the bam boo stand. Plants such as Musa sp. (Banana) were also included in the tree flora even though they were not w oody. This was done as the trunks had a DBH> 10 cm, and functionally the plants exerted similar effects as woody species, for example, shading ground flora. Ground flora plants (DBH<10 cm) were quantif ied by visual estimation within 2 x 2 m quadrats. Where plant percentage cover ranged from 5-100%, cove r was estimated to the nearest 5%. Where plants covered less than 5% of the quadrat, estimation was to the nearest 1%. There was one ground flora quadrat per 10 x 10 m tree block, totaling five ground flora quadrats per transect and 15 per site (Figure 2-7). Environmental and Anthropogenic Data All environm ental and anthropogenic variables examined are given in Table 2-2. In each 10 x 10 m transect block, data were collected for canopy closure, soil parameters, land use, distance from river and eleva tion relative to the river cha nnel margin. Canopy closure was measured in the middle of the 2 x 2 m gr ound flora quadrats using a Spherical Crown Densiometer (Concave Model). Land use was recorded for each 10 m x 10 m block based on site observations. It was not logist ically feasible to analyze soil samples from all three transects; hence, soil was only collected from the 50 m tr ansect. Soil samples were collected from two depths, 0-30 cm and 30-60 cm from the middle of the 2 x 2 m quadrats. Thus, in total 10 soil samples were collected for each of the 36 sites. Slope was measured in each block and used to calculate elevation relative to the river channel margin. Relativ e elevation was used as a proxy for flooding magnitude following Chapin & Beschta (2002).
27 On a coarser scale, major land use for each of the 36 sites was designated based on the most common land use for the 15 (10 x 10 m) blocks. Other site level categorical data collected included evidence of recreation, fire, religious activities, drainage works, surface and groundwater abstraction, pollution, braidi ng, meandering and animal activity. River hydrological parameters were also measur ed at each site including river velocity, channel depth, channel width, bankfull width, bank slope, bankfull depth and bank length. Velocity was measured using a flow meter (G lobal Water Flow Probe, model #FP101). Depth was measured with a meter rule for shallow ri vers and a sonar depth sounder for the deeper rivers (HawkEye Handheld Digital Depth Sounder). Five equally spaced readings of river velocity and depth were taken in a straight lin e across the river from each land transect (15 readings total). For South Oropouche Lowe r (SOUL) reach and North Oropouche Lower (NORL) reach, velocity and dept h readings were only taken along one transect. This was due to sampling difficulties resulting from deep water and high river velocity, respectively. Velocity and depth were used to calculate discharge using the area velocity met hod, specifically the mean section method (Gregory & Walling 1973). Channel and bankfull width were measured using either a measuring tape or a LaserAce Hypsometer. Bank slope and bank length were measured from the top of the bank to the waters edge. Ba nk was established as th e point with the first major break in slope moving landward from th e water margin. One reading was taken per transect for bankfull width, channel width, bank slope and bank length. Bank slope and bank length were used to calculate ba nk height relative to water level. This value was added to the greatest river depth for that spec ific transect to give a meas ure of total bankfull depth. Hydrological data for the three tr ansects were averaged to prov ide one value for each of the 36 sites.
28 GIS and Map Data W hile the aforementioned data were colle cted in the field, environmental and anthropogenic data were also deri ved using GIS layers and soil ma ps. Major soil type (per site) was obtained from soil maps of Trinidad and Tobago (Land Capability Survey 1971). Land ownership was obtained from topographic ma ps, (Lands and Surveys Department 1977) supplemented by interviews with residents in the area and inform ation from Forestry Officers. Catchment properties were derived from a 1994 GI S layer of watersheds in Trinidad, from the Department of Surveying and Land Information (UWI) in Trinidad. Catchment length was calculated using the most distant point met hod following Gregory & Walling (1973). Catchment shape was calculated using the form fact or method following Horton (1932). Relief was designated using the relief ratio method following Schumm (1956). Laboratory Analyses Soils were analyzed for the param eters outlined in Table 2-2. Analyses were carried out by the Central Experiment Station (C ES) in Centeno, Trinidad with the exception of soil particle size analyses that were done by the author at the Soil Science Laboratory at UWI in Trinidad. Methods of analysis followed Bartels (1996) &. Horwitz (2005). Three hundred and sixty samples were tested per parameter with 10% duplic ate testing (36) samples. Soil particle size analysis was only carried out on samples from th e 0-30 cm layer of each block; hence, only 180 samples were tested for this parameter. Data Analyses Species richness (com bined number of tree and ground flora morphot ypes) was calculated for each of the 36 sites and 12 catchments. Species richness was also calculat ed at a coarser scale on the island level, that is, on the basis of Ecoregion, geom orphology and level of human impact. The same calculations were performed for plant species diversity (Shannon Index).
29 Diversity and richness calcula tions were done using the DIVERSE program in the software package PRIMER (Plymouth Routines in Multiv ariate Ecological Research) Version 5.2.9. For these and all analyses described below, the ques tionable generic and species identifications were amalgamated with the genus or species they were most likely to be. Unid entified trees (UTs) and unidentified ground flora (UGs) were retained; ho wever, as these were distinctly different morphotypes. Specimens identified to only th e generic level were treated as separate morphotypes from specimens identified to species within that genus. While this may result in some overlap, it was felt that since the specimen could belong to any number of species within that genus, it should be treated separately. Specimens identified to family were treated in the same manner. Trees were quantified in terms of Relative Coverage (Dominance), Relative Frequency, Relative Density and the cumulative Importance Value (Brower et al. 1990). Tree relative coverage was based on basal area. Ground flora wa s quantified in terms of relative coverage, that is, percentage cover in the quadrats. Results The following sections describe envir onm ental, anthropogenic and vegetation characteristics of 36 sites along 12 rivers in Trinidad. River descri ptions are arranged by geomorphological unit, then by Ecoregion and le vel of catchment human impact following the sampling regime described in Table 2-1. Plant species found in this study are listed in Appendix A with appropriate nomenclature revisions and common names used in Trinidad. Qu estionable generic and species identifications are also included. In cases where a plant sp ecimen could not be distinguished between two candidate sepcies, both possible species names were recognised. If identification to species was not possible, the genus was listed; if the genus could not be determined then the family was
30 listed. Plants described as unident ified could not be identified to family. Unless otherwise stated, all subsequent details on characteristics and distributions of plants found in this study were based on Adams & Baksh-Comeau (Unpublished). River Profiles Caura North Geo morphological Unit; Dry Ecoregion; Low Human Impact: Photographs of the lower Caura (CAUL), middle (CAUM) and uppe r (CAUU) reaches are seen in Appendix B. All three Caura sites had gravel in block 1 of transects. The highest elevation above the river channel margin of all sites (26.10 m) was in bloc k 5 of the 100 m transect at CAUM, as seen in Table 2-3. B. vulgaris was common to all sites in the catchment. CAUL was located next to a soccer field surr ounded by businesses and industries. The site was classified as developed (DE) based on the pr esence of roads and concrete buildings (Table 2-4 & Appendix C). One transect ran along a rough gravel road. There were no species unique to CAUL, instead, weedy species like the grass Cynodon dactylon (L.) Pers. were present. Axonopus compressus (Sw.) P. Beauv (Savannah grass) co vered the soccer field and was the most abundant ground flora species at the site. In terms of the tree flora, there was only a clump of B. vulgaris present, and as a result, eleven out of 15 blocks had 0% canopy closure (Appendix D). CAUM was in a forested area next to an abandoned road. This site may have been cultivated in the past as s uggested by the presence of the introduced cultivated species Dipteryx odorata (Aubl.) Willd. (Tonka Bean). However, the site was still classifi ed as Forest (FO). CAUM had 25 species unique to this site. Miconia punctata (Desr.) D. Don ex DC. had the highest ground flora percentage cover, and B. vulgaris had the highest tree importance value. CAUU was a Government agroforestry site with mature fruit trees and timb er tree saplings. It
31 was classified as a SV site (Table 2-4) as th ere was heavy undergrowth under the timber and fruit trees, suggesting a lack of mainte nance. Timber saplings included Cordia alliodora (Ruiz & Pav.) Oken and Cedrela odorata L., two of the nine species found onl y at this site. Fruit trees at the site included Annona muricata L (Soursop), Citrus sp ., Manilkara zapota (L.) P. Royen (Sapodilla) and Syzygium malaccense (L.) Merr. & L.M. Perry (Pomerac). B. vulgaris had the highest tree importance va lue at this site, and Selaginella plana (Desv. ex Poir.) Hieron. was the most abundant ground flora species. The highest percentage of gravel in the soil (63.98%) of all 180 blocks was found in a CAUU block 1 (Table 2-3 & Appendix E). Arouca North Geo morphological Unit; Dry Ecoregion; High Human Impact: Appendix B shows Photographs of the lower (AROL), middl e (AROM) and upper (AROU) reaches of the Arouca river. All three sites studied were polluted and under privat e land ownership. A high level of human impact was evident in the well-d eveloped road network in the catchment and two sites closest to paved roads were in this catchment. Overall, the catchment had 34% forest cover (Table 2-5). Pueraria phaseoloides (Roxb.) Benth. (Kudzu), a widely distributed weed, was the only plant common to all site s along the Arouca River. AROL was sandwiched between a shopping mall and a number of larg e retention ponds. There was a well-maintained lawn between the ri verbanks and the retention ponds and a highway crossing the river just south of the sample location. AROL was cat egorized as a developed site (DE) seen in Table 2-4. The river was dredged, a nd the riverbanks were covered in low-lying unmaintained grassy, weedy vegetation. There were nine plants found only at this site (Appendix F). They included Ludwigia sp. and Cyperus surinamensis Rottb. which are both associated with moist areas in Trinidad. Sorghum sp., an introduced grass had the greatest percentage coverage
32 at the site. This site did not have any trees; henc e, there was zero percentage canopy closure at all blocks at the site. AROM was a relatively open, sunny, grassy area with fruit trees. It was classified as a SV site. There were houses uphill on both sides of the ri ver, and the site was also used for recreation. AROM appeared to be a recently abandoned agricu ltural or un-maintained agricultural site with tree crops like Persea americana Mill. (Avocado), Psidium guajava L. (Guava), Cocos nucifera L. (Coconut) and Mammea americana L. (Mame Sepo). Sixteen of the plants including the aforementioned agricultural plants were restri cted to AROM. Highest tree importance value belonged to another fruit tree Mangifera indica L. (Mango), and a sedge Scleria melaleuca Rchb. ex Schltdl. & Cham. was the most abundant ground flora species. Sample blocks at AROM had the lowest soil nitrogen and phosphate levels, <0.01 g kg-1 and 1 mg kg-1, respectively; however, these values were shared with other sites. Land use at AROU was classifi ed as Secondary Vegetation/ Abandoned Estate (SV) as it was a former cocoa ( Theobroma cacao L .) and citrus (Citrus sp.) estate. The ri ver ran parallel to a road, 5 m away. The steepest slop e (-57) of all 540 blocks in the study was at a block 1 site at AROU (Table 2-3). The lowest soil calcium leve l in all 36 sites was from a block at AROU (0.04 cmol kg-1) seen in Table 2-3. Six plants were exclus ive to this site, including two agricultural plants, Annona squamosa L. (Sugar Apple) and Zingiber officinale Roscoe (Ginger). The highest tree importance value belonged to Cecropia peltata L. (Bois Canot), which is common in disturbed areas. The most a bundant ground flora speci es (highest percentage coverage) was Pachystachys coccinea (Aubl.) Nees, which is associated w ith cocoa estates and also riparian areas (Adams & Baksh-Comeau Unpublished).
33 North Oropouche North Geomorphological Unit; Wet Ecoregion; Lo w Human Impact: The lower (NORL), middle (NORM) and uppe r (NORU) reaches of the No rth Oropouche river are shown in Appendix B. All sites in this catchment we re on privately owned la nd (Table 2-4). There were no species in common am ongst the three reaches. NORL consisted of a strip of na tural vegetation merging into an active cocoa estate with some secondary vegetation in betw een. Overall, the site was classi fied as SV, having the greatest number of sample blocks in the SV portion of the site. NORL was downstream of intensive sand and gravel quarrying operations, resulting in a sediment laden river and sand deposition on the riverbanks. As a result, the NORL block 1 soil sample had the highest sand content of 83.97%. This site also had the two highest soil silt percentages (70.72%) in block 5 followed by 67.16% in block 4. NORL also had the lowest soil pH of 3.81. The NORL river channel was braided, and the river had the highest discharge (6.42 m3s-1) of all sites (Table 2-3). B. vulgaris had the highest tree importance value, and Pueraria phaseoloides had the highest ground cover flora percentage coverage. There were five unique species at NORL, f our of which were unidentified, but also Eugenia monticola (Sw.) DC, which is normally found in forested areas. NORM was a heavily disturbed area just ups tream of a major quarrying operation and downstream of an industrial site The channel was braided like NORL. The lowest organic carbon value (<0.01 g kg-1) was found in two blocks at NORM. However, this low value was also found at two other sites. NORM also had the highest soil pH valu e (8.19). There was a narrow strip of vegetation on the riverbank, beyond which there was a large burnt field resulting in a land classification of GR. B. vulgaris had the highest tree importance value, and Panicum maximum Jacq. had the highest percentage coverage in the ground flora. P. maximum was one of five species exclusive to this site; however, it should be noted that ther e were occurrences of
34 Panicum sp. at other sites, but at NORM, the pl ants bore flowers, which allowed identification to species level. NORU consisted of a patch of native forest sandwiched between abandoned cocoa/coffee plantations. This patch of forest was perhap s retained, since the area was on a steep rocky outcrop as opposed to the flatter land on either side. The site wa s classified as FO. NORU had the greatest bankfull depth of 11.29 m and the steepest bank slope of -50.67. It was one of the sites with <0.01 g kg-1 nitrogen levels and also had the lowest soil electroconductivity (EC) value of 0.013 mS cm-1. Hieronyma laxiflora (Tul.) Mll. Arg., a fore st species, had the highest importance value, and Coffea sp. had the highest ground flora percentage cover at this site. NORU had 25 unique species including H. laxiflora, Ryania speciosa Vahl, Calophyllum lucidum Benth. and the ground flora plant Miconia nervosa (Sm.) Triana. R. speciosa, C. lucidum and M. nervosa are normally found in moist forested areas. Quiina cruegeriana Griseb., which was found only at this site, has been previously reported in riparian areas, while Psychotria capitata Ruiz & Pav. has been noted in swampy areas. Another NORU exclusive species is Chimarrhis cymosa Jacq, which while not specifically reported in riparian areas, is commonly called Bois Riviere (River Wood). Four of the unique species at NORU were ferns including the tree fern Cnemidaria spectabilis (Kunze) R.M. Tryon, which has previously been reported near rivers. Aripo North Geo morphological Unit; Wet Ecoregion; High Human Impact: Appendix B shows Photographs of the lower (ARIL), middle (ARIM) and upper (ARIU) reaches of the Aripo river. This catchment had the highest basin re lief of all 12 catchments, with the greatest difference between the highest and lowest points (787.4 m). It also ha d the highest relief ratio of 0.055, which is the ratio of basin relief to catchme nt length (Table 2-5). ARIM and ARIL had
35 braided channels. All th ree sites had gravelly riverbeds; however, gravel was not found in the soil sampled at ARIL. All three Aripo sites had Justicia secunda Vahl and Spondias mombin L. The former is associated with moist shady areas in Trinidad, while S. mombin is an introduced, naturalized plant common in forests and swam py disturbed areas (A dams & Baksh-Comeau Unpublished). ARIL was classified as grassland (GR) as seen in Table 2-4, due to limited tree cover, low canopy closure, and a dominance of vines, gras ses and low-lying vegetation. The entire area was swampy and pitted with small ponds. ARIL had 36 plant species, of which six were found only at this site. These included Cassia reticulata Willd., Hymenachne sp., Ludwigia peruviana (L.) H. Hara and Commelina erecta L. (Watergrass), of which the la tter three plants are associated with wet, moist, or riparian areas (Adams & Baksh-Comeau Unpublished). There were only two tree species at this site re presented by one specimen of Vismia laxiflora Reichardt and four Erythrina glauca Willd. specimens. E. glauca is an introduced, naturali zed plant in Trinidad. It is found in low-lying areas and is comm only called the Water Immortelle. A vine, Ipomea sp., had the highest ground flora percen tage coverage at this site. ARIM was classified as an agricultura l site (AG), as it was located in a Carica papaya L. (Papaya) field. There was also a patch of secondary forest at this site at the 100 m transect. The river channel was modified by the insertion of large concrete columns to block water flow to create pools for bathing. This site was also downs tream of a water abstraction point. Papaya was one of the 12 plants exclusive to the site, seven of which were weeds or agricultural plants. The highest tree importance value belonged to Hura crepitans L. (Sandbox), a typical secondary forest species, and the highest percentage coverage in the ground flora belonged to Parthenium hysterophorus L., a weedy species found under papaya plants at this site.
36 ARIU was a recreational area located downstream and downhill from a nature lodge. The site was crisscrossed by a number of tributaries and was the highest site in the study at 228.60 m above sea level (Table 2-3). The si te was classified as forested (FO) as the majority of sample blocks at this site (9/15), had forest cover (Appendices 2 & 3). ARIU had the highest soil calcium level (26.69 cmol kg-1) of all 360 soil samples collected acr oss all sites (Table 2-3). This value was found at the 30-60 cm soil depth in block 4, the second to last landward block of the transect. The next seven highest calcium readings were also found at the ARIU, which also had 89 g kg-1, the highest organic carbon level found in th is study (Table 2-3). One sample block in ARIU also had the lowest phosphate level of 1 mg kg-1; however, this value was shared with blocks at other sites. ARIU had a strip of trees on the riverbank beyond which there were shallow ponds used for growing Rorippa officinale R.Br. (Watercress). R. officinale was one of the plant species unique to ARIU site (Appendix F). Only seven species were exclusive to this site including Chrysothemis pulchella (Donn) Decne, an ornamental plant normally associated with T. cacao (Cocoa) plantations. The highest tree impor tance vale at this site belonged to Erythrina poeppigiana (Walp.) O.F. Cook, an introduced, naturaliz ed species normally associated with cocoa plantations. Also found at this site was the lycopod Selaginella plana which had the highest ground flora percentage cover. Caparo Central Ge omorphological Unit; Dry Ecoregion; Low Human Impact: Photographs of the lower (CAPL), middle (CAPM) and upper (CAPU) reaches are provided in Appendix B. The Caparo catchment had the smallest form fact or of 0.17 (ratio of area to the square of catchment length). Overall, only five tree sp ecies were found across a ll three sites, and no species were common to the three sites.
37 CAPL was in a sugarcane ( Saccharum officinarum L.) field; however, sugarcane was only found in transect blocks 4 and 5. The river channe l was covered in aquatic vegetation. This site was classified as grassland (GR) seen in Table 2-4 as grasses and weeds such as Malachra fasciata Jacq. and Dichanthium caricosum (L.) A. Camus replaced th e sugarcane closer to the river. The aforementioned species were two of five species unique to this site. The most abundant ground flora plant at CAPL was a grass only id entified to the family level. There were no trees at CAPL resulting in a 0% canopy closure in all blocks at the site During field visits, dredging was taking place upstream of the samp ling area, and the existing riverbank morphology suggested that the site had been dredged the year before. CAPL had the widest bankfull width in the study (31.67 m). The two highest soil magnesium levels were in sample blocks at CAPL (8.34 cmol kg-1) in the 30-60 cm soil depth level and 7.79 cmol kg-1 at the 0-30 cm depth. CAPM was a SV site located a bout 300 m behind a house. There was a strip of trees within 40 m of the riverbank, beyond which a series of gr ass-covered fields extended to the house. The site had a high level of human traffic as indicated by well-worn trails and litter along the river. The area also appeared to be subj ect to fires as suggested by blacken ed tree trunks at the site. In terms of soil properties, CAPM ha d one sample block with <0.01 g kg-1 nitrogen, the lowest value shared with three other sites. CA PM was the only site in the study that had Crudia glaberrima (Steud.) J.F. Macbr. This species is found in swampy areas. Apart from C. glaberrima five other species were restricted to th is site. The highest importance value among the trees belonged to Syzygium cumini (L.) Skeels (Gulub Jamoon), an introduced, naturalized tree. Flemingia strobilifera (L.) R. Br. (Wild Hops) a weedy, introduced species had the highest ground flora coverage.
38 CAPU was an AG site located in a sugarcan e field and like CAPL dredging was taking place upstream during field sampling. There were six species unique to CAPU including two grasses Echinochloa colona (L.) Link and Leptochloa virgata (L.) P. Beauv. There was a clump of B. vulgaris Schrad. ex J.C. Wendl (Bamboo) in a bl ock 1, but no other trees at this site. Saccharum officinarum (Sugarcane) had the highest percen tage coverage at this site. Couva Central Ge omorphological Unit; Dry Ecoregion; High Human Impact: Photographs of all Couva sites are seen in Appendix B. The cat chment had the lowest forest cover of all 12 catchments (17%) seen in Table 25 and all three sites in the catch ment were polluted. All three sites had B. vulgaris F. strobilifera and J. secunda. COUL was located in a S. officinarum (Sugarcane) field; however, the river was deeply incised such that sugarcane was only found in bloc ks 4 and 5 of the transe cts. Blocks 1-3 had native forest species and heavy canopy cover, and as a result, the site was classified as FO (Table 2-4). Fires appear to be common at the site. Only three species were exclusive to COUL in this study, two were uniden tified, but the third, Machaerium tobagense Urb. was a generalist species found throughout Trinidad. COUL had the highest total nitr ogen level in the study, 36 g kg-1 found in blocks 3 and 4 (0-30 cm depth). B. vulgaris had the highest importa nce value at the site and F. strobilifera the highest ground fl ora percentage cover. COUM was located within 60 m of a house and was classified as a SV site (Table 2-4). Vegetation transects extended to the lawn surroundi ng the house. There was evidence of fire at the site. There were six unique pl ants including the weedy species Justicia pectoralis Jacq. (Appendix F) and a cashew tree ( Anacardium occidentale L.) in the houses backyard. The highest phosphate level in the study (151 mg kg-1) was found at this site at a depth of 0-30 cm in
39 block 3. Like COUL, B. vulgaris had the highest importan ce value at the site, and F. strobilifera (L.) R. Br. had the highest ground flora percentage cover. COUU bordered an old cocoa estate and was cl assified as a SV site. There were three unique species at this site: Gibasis geniculata (Jacq.) Rohweder, Ludwigia decurrens Walter and Priva lappulacea (L.) Pers. Like the other Couva sites, B. vulgaris had the highest tree importance value, but F. strobilifera was replaced by Pueraria phaseoloides as the most abundant ground flora plant. Lebranche Central Ge omorphological Unit; Wet Ecoregion; Low Human Impact: Appendix B shows all the lower (LEBL), middle (LEBM) and uppe r (LEBU) reaches of the Lebranche river. At 47.09 km2, Lebranche was the smallest catchment in the study and also, along with the Poole catchment, had the lowest maximum basin relief of 68 m (Table 2-5). Seven species were common to all three reaches. These included Heliconia bihai/spatho-circinada, T. cacao, Spondias mombin, Tectaria sp Cecropia peltata, Adiantum sp. and Bignoniaceae 1. The Lebranche catchment had the highest amount of B. vulgaris in the study, almost 46% of the total B. vulgaris basal area across all sites. There was no evidence of recreation, fire or human modification at any of the LEB sites (Table 2-4). While the catchment is characterized as low human impact with a forest cover of 63%, the three randomly chosen sites were in abandoned cocoa estates. LEBL was situated 70 m from a major paved road. The site had <0.01 g kg-1 carbon in a block 1 sample, the lowest value for the study, also shared with blocks at three other sites. LEBL had Cissus sp., Clidemia sp. 2 and Marsdenia macrophylla (Humb. & Bonpl. ex Schult.) E. Fourn. and one unidentified species found only at this site. B. vulgaris had the highest importance value, and H. bihai/spatho-circinada had the highest ground flora percentage
40 coverage. Like, LEBL, B. vulgaris had the highest importance value, and H. bihai/spathocircinada had the highest per centage coverage at LEBM. LEBM had two unidentified species and Costus sp. unique to that site. LEBM had two blocks with 1 mg kg-1, the lowest soil phosphate level shared with three other sites. Unlike the other two sites, LEBU had Costus scaber Ruiz & Pav. in greatest abundance in the ground flora and Ficus maxima Mill. with the highest tree importance value C. scaber is found in disturbed, shady areas often in association with cocoa plantations. F. maxima is widespread across Trinidad. LEBU had eight species unique to that site including a seedling of Pterocarpus officinalis a noted swamp species. The other seven unique species were all ground flora plants, in par ticular, vines like Dioclea reflexa Hook. f., and Mikania scabra DC. These were found along riparian transect s and also on the dry river bed of LEBU. Other unique species such as Drymonia serrulata (Jacq.) Mart. and Palicourea crocea (Sw.) Roem. & Schult. are normally found in wet areas. Passiflora serratodigitata L. is found in moist disturbed areas, while Lasiacis ligulata Hitchc. & Chase is a known riparian plant. Cumuto Central Ge omorphological Unit; Wet Ecoregion; High Human Impact: Photographs of the upper (CUMU) middle (CU MM) and lower (CUML) reaches are presented in Appendix B. All sites were on privately ow ned land. There were no recreationa l activities and no evidence of pollution or fire (Table 2-4). Two weeds, Pueraria phaseoloides and Blechum pyramidatum (Lam.) Urb. were found at all three sites along the river. CUML was classified as SV for this study as it was an un-maintained agricultural estate. Agricultural trees at this site included Citrus sp., Syzygium malaccense and a timber species Swietenia macrophylla King (Mahogany). S. macrophylla was only found at CUML, as was the palm Euterpe oleracea Mart. and Simarouba amara Aubl. E. oleracea is common in low-lying
41 moist areas, while S. amara is normally found in forested areas. Overall, six species were unique to this site. While not exclusive to CUML, Bambusa vulgaris had the highest importance value, while Justicia secunda had the greatest ground flora percentage cover at this site. CUMM was a well-maintained agricultural ar ea (AG). There were citrus trees and a closely cropped lawn under the trees. River morphology suggested past dredging at the site. Unique species consisted of four uni dentified plants in addition to Cyperus sp. and Ludwigia sp. Ludwigia sp. is associated with moist areas in Trinidad. Citrus sp. had the highest importance value, and the lawn grass Axonopus compressus had the highest ground flora coverage. CUMU had a dry riverbed. The site was forest ed, extending into an open agricultural area with tree crops and a ground cover of weedy vegetation. It was clas sified as AG as eight of the 15 sample blocks were in the agricultural area. There were six species found only at this site, including one tree Zanthoxylum martinicense (Lam.) DC and five ground flora plants. These unique ground flora species included a weed Urera baccifera (L.) Gaudich. ex Wedd and Commelina diffusa Burm. f. (Watergrass). C. diffusa is associated with moist and riparian areas in Trinidad. Like CUML, J. secunda had the highest ground pe rcentage coverage and B. vulgaris the highest tree importance value. Penal: South Geomorphological Unit; Dry Ecoregion; Low Human Impact Photographs of the lower (PENL), middle (PEN M) and upper (PENU) reaches are seen in Appendix B. Penal had the highest form factor of all catchments (1.83) due in part to its shortest catchment length (6.62 km). All three reaches ha d dry riverbeds and were on public land, as the river was located entirely in th e Southern Watershed Reserve. Bactris major Jacq. and Spondias mombin were found at all three sites in this catchment. B. major is a clump-forming palm species and has been reported in swamp and riparian areas (Adams & BakshComeau Unpublished).
42 There was evidence of hunting at all sites and abandoned marijuana plots ( Cannabis sativa L.) at PENM and PENL. PENL was classified as a fo rested site (FO), as seen in Table 2-4. The highest importance value belonged to Bravaisia integerrima (Spreng.) Standl. (Jiggerwood), a tree found in wet forests in Trinid ad, while the highest percentage coverage belonged to a vine Paullinia leiocarpa Griseb. There were 14 species unique to this site. These included Bursera simaruba (L.) Sarg., a dry forest species and also Chionanthus compactus Sw. and Nectandra rectinervia Meisn., two generalist tree species. Two othe r unique species were Sansevieria hyacinthoides (L.) locally known as Mother-in-laws Tongue, a ground flora plant, and the tree Crescentia cujete L. (Calabash), both introdu ced, cultivated species. PENM was approximately 1.9 km away from a pa ved road, the site furthest away from a road. It was classified as a forested site. Bactris major had the highest percentage coverage in the ground flora and Bravaisia integerrima the highest importance value. There were nine species found only at PENM including the trees Capparis baducca L., found in wet forests in south Trinidad, and Zanthoxylum microcarpum Griseb. (Lepinet), another wet forest species, but not restricted to south Trinidad. PENU had the shallowest bankfull depth in the study (0.84 m). The site was in a Teak plantation ( Tectona grandis L. f.), and as it was the dry se ason, the teak trees had shed their leaves. As a result, 11 of the 15 sample blocks had canopy closures less than 20%. The teak plantation at PENU was categorized as AG, as it was a well-maintained m onoculture with little undergrowth. T. grandis had the highest importance value and Bactris major the highest percentage coverage in the ground flora. T. grandis was only found at PENU, as were the trees Diospyros inconstans Jacq. and Machaerium robiniifolium (DC.) Vogel. Both D. inconstans and M. robiniifolium are dry forest species.
43 South Oropouche South Geomorphological Unit; Dry Ecoregion; High Human Impact: South Oropouche was the largest catchm ent in the study (438.67 km2). There was evidence of fire and pollution at all sites. All reaches had Acroceras zizanioides (Kunth) Dandy and Saccharum officinarum (Sugarcane). Appendix B shows the lower (SOUL), middle (SOUM) and upper (SOUU) reaches of the river. SOUL was located at a large, dredged, straight ened canal, part of a network of canals in the South Oropouche watershed. Dredging and strai ghtening at this site may have taken place more than 10 years ago, as there were mature tree s in the dredged areas. The site was classified as SV, as it included sugarcane fields and fruit tr ees. There were houses within 80 m of the site. S. officinarum had the highest ground cover, and Bambusa vulgaris had the highest importance value. Seven unique species were found at this site including Hymenachne amplexicaulis (Rudge) Nees., Imperata brasiliensis Trin., Urochloa mutica (Forssk.) T.Q. Nguyen and Terminalia catappa L., I. brasiliensis is associated with fire prone areas. H. amplexicaulis is a known swamp and riparian species as is U. mutica, an introduced grass (Para Grass). The two highest soil EC levels were at SOUL (9.60 mS cm-1) at the 30 cm level and 7.85 mS cm-1 at the 60 cm level, both in block 1 of the transect where soil was collected. SOUM was at another dredged, straightened canal The site was in a sugarcane field that was already burnt and harvested. There were only two tree specim ens, and as a result 12 of 15 blocks had 0% canopy closure. A grass, Eriochloa punctata (L.) Desv. ex Ham, had the highest ground cover, and Erythrina glauca had the highest tree importance value. The other tree species present at the site was Cordia collococca L. The grass Eriochloa punctata is normally found in moist disturbed areas. The site did not have any unique species.
44 SOUU was not part of the canal system in the South Oropouche watershed. The site was in a burnt, harvested sugarcane field. At the time of sampling sugarcane had started re-sprouting to such an extent that it had th e highest ground flora coverage. Sapindus saponaria L., a tree found in riparian areas, had the highest importance value. There were three unique species including Paullinia pinnata L., a moist forest ground flora species. Moruga South Geomorphological Unit; Wet Ecoregion; Lo w Human Impact: Photographs of the lower (MORL), middle (MORM), and upper re ach (MORU) are seen in Appendix B. The Moruga catchment had an 84% forest cover value, the highest in the st udy. All three sites had Costus scaber and Mora excelsa Benth. in common. All three sites were classified as FO (Table 2-4) and had evidence of hunting and timber harv esting. They were located in the Victoria Mayaro Forest Reserve. Although it is a forest reserve, the area is also controlled by the National Petroleum Company of Trinidad and Tobago (P ETROTRIN), and as such, was crisscrossed by access roads and pipelines. MORL was approximately 1 km from a paved roa d. It was also at the lowest elevation in the study, 2.3 m above sea level. The lowe st phosphate level recorded, 1 mg kg-1, was found in two sample blocks at MORL, but this value wa s shared with blocks at five other sites. Leptochloa sp. was the most abundant pl ant in the ground flora, and M. excelsa had the highest importance value among the trees. Although Leptochloa sp. could not be identified to species, Leptochloa longa Griseb. has been noted in riparian ar eas. MORL had 15 species found only at this site, one of which, the tree Mouriri rhizophorifolia (DC.) Triana, is common in south Trinidad in forested and swampy areas. All ot her exclusive species we re ground flora plants such as Cleome gynandra L., Heliotropium angiospermum Murray and Lastreopsis effusa (Sw.)
45 Tindale var divergens (Willd. Ex Schkuhr). These th ree species were either weedy or common in disturbed areas. MORM was also located 2.3 m above sea level, the lowest in the study (Table 2-3). It was within 500 m of a road and 300 m of an oil pump. Eight of the 15, 10 x 10 m blocks had over 95% canopy closure, including three blocks with 100% canopy closure. Only five blocks in the entire study had 100% canopy closure, sugges ting heavily shaded conditions at MORM. However, it should be noted that block 1 (closest to the river) in each transect at MORM had 0% canopy closure. MORM had the highest soil potassium values (21 cmol kg-1) found in one block at the site but the lowest magnesium level (0.03 cmol kg-1) found in another block at the 30-60 cm soil depth. Like MORL, Mora excelsa also had the highest importance value at this site, while the most abundant ground flora species was Piper hispidum Sw. P. hispidum is found in swampy areas. There were four unique sp ecies at this site including one tree Terminalia dichotoma G. Mey, which is found in forests in south Tr inidad. While this tree is not noted to be a riparian or swamp species, the common name is Water Olivier. Two of the other three unique species were weedy species, namely Cleome spinosa Jacq. and Wedelia trilobata (L.) Hitchc. M. excelsa had the highest tree importance value at MORU like the other two sites, but the most abundant ground flora plant was Ischnosiphon arouma (Aubl.) Krn., commonly called Tirite. This plant is common in low-lying moist forested areas. MORU had 11 species unique to this site including the tree Crateva tapia L., which is restricted to south Trinidad. Ground flora plants exclusive to this site included Pavonia castaneifolia A. St.-Hil. & Naudin and Pharus latifolius L., both found in moist areas, as well as the fern Lomariopsis japurensis (Mart.) J.Sm. and Piresia sympodica (Dll) Swallen, both noted riparian species.
46 Poole South Geomorphological Unit; Wet Ecoregion; High Human Impact: Appendix B shows photographs of the lower (PO OL), mi ddle (POOM) and upper reaches (POOU) of the river. Poole had the longest ca tchment length of 32.70 km and th e lowest relief ratio of 0.002. The catchment had 53% forest cover, and all th ree reaches were in abandoned cocoa and coffee estates. However, it should be noted that there were no cocoa plants collec ted within transects at POOL. There was river meandering at all three s ites. All land was privately owned, and there were caimans ( Caiman crocodilus ) at POOL and POOM (Table 2-4). All three sites shared Inga ingoides (Rich.) Willd., Coffea sp., Costus scaber, and the ferns Adiantum sp and Tectaria sp. C. scaber is associated with cocoa plantations, and I. ingoides is found in moist, disturbed areas. While POOL was in a cocoa/coffee plantation, there was a patch of native vegetation in a steep part of the site. Coffea sp. had the highest gr ound flora coverage, and Erythrina poeppigiana had the highest importance value. Un ique species at the site included Myrcia splendens (Sw.), found in moist forests, and Buchenavia tetraphylla (Aubl.) R.A. Howard DC. (Yellow Olivier), which was another forest species. At POOM, Heliconia bihai/spatho-circinada had the highest ground flora coverage, and Bambusa vulgaris had the highest importance value in the tree flora. Unique species at POOM consisted of six unidentified species. POOM also had fruit trees, namely Syzygium malaccense and Musa sp. There was an active agriculture patch on the riverbank consisting of Colocasia esculenta (L.) Schott. POOU had the narrowest channel width of 1.79 m. At this site, Coffea sp. had the highest ground flora, and Pisonia cuspidata Heimerl., a widespread species had the highest importance value. Unique species included ni ne unidentified plants and one tr ee tentatively identified as
47 Xylosoma seemannii Ficus trigonata L. and Hypolytrum longifolium (Rich.) Nees were also restricted to POOU. H. longifolium is found in moist, shady areas. Summary of Environmental and Anthropogeni c Characteristics of Riparian Z ones A total of six land use types were noted acro ss the 36 sites. These were Developed (DE), water (WA), Secondary Vegetation (SV), Forest (FO), Agriculture (AG) and Grassland (GR). The only one instance of a WA site, was in bl ock 5 of the AROL reach where the transect extended into a retention pond. The most comm only occurring land use was SV, found at 197 sample blocks, followed by FO at 142 blocks. Five of the seven blocks with 100% canopy closure blocks were in FO blocks. Of the 144 sample blocks with 0% canopy closure, 63 were agriculture blocks and 48 were grassland sample blocks. On a coarser scale, 15 of the 36 sites were classified as SV, seven were AG, nine were FO, four GR and one was DE. Seven of the SV sites were abandoned cocoa/coffee plantations. Agricultural sites were well-maintained, cultivated sites with little undergrowth and little canopy cove r. They included papaya fields, citrus orchards and sugarcane fields. Five of the nine fore sted sites were in the South Geomorphological Unit. Twenty-five of the 36 sites were on privately owned land. The public lands were in Forest Reserves, former State owned sugarcane estates or public recreational areas. None of the 36 sites had evidence of religious activities or groundwater abstraction. Twenty-one sites had evidence of recreational activities in cluding hunting, fishing, bathing and campi ng. In particular, evidence of hunting was found at all Moruga site s in the Victoria Mayaro Forest Reserve in south Trinidad. Conspciuous fauna were pres ent at nine sites including Caiman crocodilus (Caimans), Alouatta seniculus (Red Howler Monkey) sighted at LEBU and Lontra longicaudis (Otter) at ARIM. There were 22 polluted sites character ized by solid waste or a stench either in the riparian area or from the river. Twelve site s had evidence of fire.
48 The seven highest sites (elevation relative to s ea level) were in the Northern Range. The four sample blocks with the highest elevation relative to the river cha nnel were also in the Northern Range. The four steepest slopes across all blocks were in the Northern Range, all at block 1 sites on river channel margins. Five rivers had dry channel beds including, CUMU, LEBU, PENM, PENU and PENL. There was meandering at 14 site s and braided channels at four sites. There were no meandering river ch annels or dry riverbeds in the Northern Range. Twenty-three of the 36 sites had river discharges lower than 0.1 m3, indicating near stagnant conditions. Only 10 of 36 sites and 17 of 180 blocks had gravel. Overall, the most common soil type was Lebranche clay found at nine sites. This series is categorized as Aeric Tropaquepts under the USDA soil classification system and Dy stric Gleysol under the FAO soil classification scheme (Paul 2001). Summary of Plant Composition and Structure Importance value, species richness and diversity B. vulgaris had the highest basal area and subseq uent relative coverage and im portance value across all sites su rveyed (total area=0.054 km2) seen in Table 2-6. Tectona grandis, Cecropia peltata and Theobroma cacao followed in importance value. B. vulgaris was found at the greatest number of sites (15), giving rise to a relati ve frequency of 4.62%, whereas Tectona grandis was found only at one site with a relative frequency of 0.31%. T. grandis had the highest number of specimens (80), with a resulting relative de nsity of 9.30%. Among ground flora species, Coffea sp. had the highest relati ve coverage followed by the lycopod Selaginella plana J. secunda and Pueraria phaseoloides (Table 2-7). P. phaseoloides was found at the greatest nu mber of sites (18). AROM had the highest overall species richness of all 36 sites (64) followed by NORU (60 species) and LEBU (58) species (Table 2-8). Th e lowest species richness was at SOUM, which
49 had eight species. Both NORU a nd CAUM had the highest number of unique species (25), while CAUL had no unique species (Appendix F). Highest species dive rsity was at NORU, with a Shannon index value of 3.89, followed by LEBU and AROM, both with a value of 3.80. The lowest diversity (1.15) was at PENU. SOUM and SOUU also had low diversities of 1.48 and 2.1, respectively. Species richness and diversity per re ach are provided in Table 2-8 along with most important tree species and ground flora plants with the highest percentage coverage. On a catchment basis, North Oropouche had the highes t species richness (123), and South Oropouche had the lowest species richness of 43 species (See Table 2-9). The North Oropouche River also had the highest species diversity and the South Oropouche River th e lowest (Table 2-10). In terms of geomorphological units, the North Unit ha d the highest species diversity (5.20) and the highest species richness (292 sp ecies) as seen in Table 2-11. The Wet Ecoregion had a higher species richness (351) and divers ity (5.18) compared to 314 species and a diversity of 5.02 in the Dry Ecoregion. When combined, the six impacted catchments had a total species richness of 337 and diversity of 5.17, while the low impact catchments had a species richness of 323 and a diversity of 5.04 (Table 2-11). Plant taxonomy The Poaceae fa mily had the most number of morphotypes (species and unidentified specimens) represented in the study (43). This was followed by Leguminosae (40), then Asteraceae and Rubiaceae, with 19 specimens each. T. grandis had the highest number of specimens (85) followed by Mora excelsa (73) and B. vulgaris (68). These numbers included both mature trees and seedlings of the species found in the ground flora. P. phaseoloides (Roxb.) Benth. had the next highest number of morphotyes (64). Th is is a ground flora species as is Costus scaber which followed P. phaseoloides with 57 morphotyes.
50 Ninety-four plant families were identified across the island including eight fern families and one lycopod (Selaginellaceae). All other plan ts were angiosperms. Within the 94 plant families, there were 426 morphotypes, including family, generic and species level morphotypes as well as those morphotypes, with questio nable identifications. These 426 morphotypes belonged to 330 species and 270 genera. The species lis t with plants identified to at least family level for all the sites surveyed is shown in Appendix A. Twenty-eight of the species f ound are associated with rivers in Trinidad; 33 species have been previously found in swamps and six are found in both swamps and along rivers (Adams & Baksh-Comeau Unpublished). These species are highlighted in Ta ble 2-12. Forty-nine plant species were introduced to Trinidad. These included agricultural crops, fru it trees, timber trees, forage grasses and ornamental plants. Only one of the plants found was endemic to Trinidad. This was Philodendron krugii Engl. found at the Lebranche Upper Reach (LEBU), Aripo Upper Reach (ARIU) and Caura Upper Reach (CAUU) sites. A total of 2894 plant specimens were found w ithin the 36 study sites, distributed among 502 morphotypes. These specimens were sub-di vided into 2034 ground flora specimens, 860 trees, and included 48 unidentified ground flora specimens (UG) and 36 unidentified tree (UT) morphotypes. All other specimens were iden tified to at least the family level. Discussion Anthropogenic Characteristics of Riparian Z ones in Trinidad Half of the catchments studied were categori zed as having a low level of human impact based on forest cover (Table 2-1). However, of the 36 randomly chosen sites in the catchments, only nine were in forested areas. This could refl ect the random site selection process, but it also may point to a high level of human interference along rivers in Trinidad. It may be that even in the less impacted catchments, riparian zones were preferred agricultural or settlement sites.
51 Riparian areas have traditionally been areas of high human interference worldwide especially for agriculture, settlement, trans port and recreation (National Re search Council 2002). On a finer scale, human activity occurred in clos e proximity to the river margin at the sites. At agricultural sites, crops were found within the second block (10-20 m) of the 50 m transect, for example, Saccharum officinarum (Sugarcane) at the CAPU site. This may be due to, inter alia an absence of nationa l regulations regarding riparian se tbacks or buffer zones, allowing agriculture, industry and housing to take place at the rivers e dge. The implication of human activity so close to the river channel margin is that vegetation collected during this study may be more reflective of land use practices and other hu man interference, than hydrological parameters, which are generally regarded as the major control on riparian ve getation composition and structure (Tabacchi et al. 1998). The relativ e importance of hydrological vs. anthropogenic variables will be explored further in Chapter 3. Apart from the direct replacement of riparian plants with agricultural crops, agricultural activ ity may also have indir ect effects on vegetation. Sugarcane fields at SOUU and SOUM were samp led after fields were burnt, a practice that facilitates easier harvesting. At these agricultural s ites, burning could also extend to noncultivated riparian areas. Unpl anned fires are also common in th e dry season in Trinidad (Singh 2001) and may have altered plant species compositi on and structure at SV sites such as CAPM and POOU. Apart from agricultu re, it appears that housing an d urbanization may have also shaped riparian vegetation in Trinidad. For exam ple, this was seen at CAUL, where roads and buildings replaced plants Past human activity may still be shaping riparian vegetation in Trinidad. Seven riparian sites were former cocoa plantations. In the case of the Lebranche River, a low impact river (Table 2-1), all three reaches had abandoned cocoa plantations. Cocoa was an important
52 agricultural crop in Trin idad during the early 20th century, occupying approximately 90 000 hectares in 1917. The industry collapsed due to a combination of disease, unfavorable prices and competition from other countries (Bekele 2008). As a result, many estates were abandoned and are now secondary growth (SV) sites. The SV sites not only included abandoned cocoa estates, but also abandoned citrus fields at CUML and AROU. Agricultural abandonment is on the rise in Trinidad. Overall, the agricultural sector has been steadily declining and only contributed 0.6% to Trinidads GDP in 2007 compared to a 62% c ontribution from the indus trial sector (Central Intelligence Agency 2008). Deliberate physical modificati on of sites could also have influenced the vegetation collected. At ARIM for instance, residents altered the riverbed to create pools for bathing. This could have also altered the flooding regime in this area and impacted riparian vegetation. At CAUM, there was direct plant removal for firewood and campsite construction. During sampling in 2007, dredging was taking place at CA PU and CAPL. Excavators deepened the river channel and cleared all vegetati on within 20-30 m of the water margin. Sampling at these sites took place downstream of dre dging activities, but based on th e angular channel morphology and bare riverbank slopes at the actual transect points, it is likely th at dredging took place at those points perhaps within the last 1-3 years. Regular channel modification could have resulted in the dominance of short lived or fast growing plant species at these riparian sites in response to continuous vegetation removal. Dredging is carrie d out regularly along rivers in Trinidad to reduce flooding in nearby settlements, but the absence of the normal flooding regime can alter riparian vegetation life histor y and distributional patterns (Fre eman et al. 2003). Dredging can also block connections to backwaters and tribut aries, again with possible changes in riparian plant species composition as well as riparian zone width and shape (Wissmar & Beschta 1998).
53 Forested sites were also not free from human impact. At FO sites along the Moruga River, there was evidence of hunti ng and timber harvesting. An oil pump was also located approximately 300 m from MORM. The PENM and PENL forest sites were close to skidder trails, and in the case of PENM, one of the vegetation transe cts bisected an abandoned marijuana field. Hunting trails, skidder trails and marijuana plots all resulted in dir ect removal of riparian vegetation at the sites studied. Th e high level of human impact at the study sites has implications for the selection of riparian reference systems for conservation purposes. This will be explored further in Chapter 3, but it should be noted here that there was evidence of either present or past human activities at all site s studied, thus, none can be regarded as pristine. Environmental Characteristics of Riparian z ones in Trinidad Sampling was carried out during the dry season, thus the low discharg es and dry riverbeds found were expected. For this reason, bankfull dept h was also measured at each site to provide an indication of water levels during the rainy season. As was also expected, site elevation and slope values were highest along rivers of the Northern Range Geomorphological Unit. The soils parameters examined included chemical and physical variables that were likely to impact plant growth. Levels of the variables measured seemed generally to agree with typical values of major soil types found in the areas sampled (Brown & Ba lly 1968). The very high soil EC values at SOUL may be a sampling error. While estuarin e areas were avoided in this study, SOUL may have been under tidal influence even though the site was more th an 10 km away from the river mouth. High soil phosphates values at ARIM, ma y be linked to fertilizer application in the papaya field. High phosphates at COUM may be due to wastewater runoff from the house located uphill of the transects. Generally speaking, riparian soil properties are shaped by bot h terrestrial and hydrological influences. Hydrology affects riparian soil thr ough flooding and chemical exchange between the
54 river channel and riparian zone via the hyporheic corridor (Bou lton et al. 1998). However, sampling took place during the dry season when the rivers had low flow or stagnant pools. As a result, the influence of the hyporheic zone was probably minimal, especially as soil depths sampled were only 0-30 cm and 30-60 cm. It is likely; however, that past flooding events have influenced both physical and chemical propertie s of the soil. High sand levels at NORL, for instance, may be due to deposition of mined sand from farther upstream during past flooding events. Riparian Plant Composition and Vegetation Types in Trinidad There are about 2200 flowering pl ant species and 600 ferns reco rded for T rinidad (Nelson 2004). During this study, 502 morphotypes were f ound, including 20 species of ferns and two lycopods. This is a relatively high number of sp ecies considering that th e total sample area for all 36 sites was 0.054 km2 compared to the total area of Tr inidad, which is approximately 4800 km2. High species richness is characteristic of ripa rian zones linked to gr eat levels of physical heterogeneity and physical disturbance (Stanl ey 2001). The high number of species found during vegetation sampling may not only be linked to riparian characteristic s, but also to variations in geomorphology and rainfall among sites. These possi ble variations were de liberately included in the sampling protocol to capture the range of potential riparian vegetation types. This will be analyzed in more detail in Chapter 3. Typical riparian species for Trinidad will be designated after an examination of riparian environmental variables in Chapter 3. There is however, supporting info rmation from herbarium records detailed in Adams & Baksh-Comeau (Unpub lished), which identified possible riparian species, based on their distribution and growth ha bits. Table 2-12 highlights plant species from this study, which according to herbarium records, are associated with rivers and freshwater swamps in Trinidad. A number of sp ecies in Table 2-12 are weedy including Commelina diffusa
55 C. erecta and S phenoclea zeylanica Gaertn Species such as Spondias mombin Acroceras zizanioides Lasiacis ligulata and Renealmia alpinia (Rottb.) are common in both riparian and disturbed areas. Weedy species were found along rivers even at forested sites, for example, W. trilobata found at MORM. Overall, 13 of the ripa rian species listed in Table 2-12 were grasses, including five introduced species. Apart from herbarium records described in Adams & Comeau (Unpublished), there is some available literature on the geographic distribution of species collected in this study. For instance, Beard (1946) noted Crudia glaberrima (Steud.) J.F. Macbr. in swamp hollows and waterlogged areas around the Nariva freshwater swamp. C. glaberrima was found at CAPM in this study. Pterocarpus officinalis which is also listed in Table 2-12, was found by Beard (1946) in large stands at the mouth of the Nort h Oropouche river. However, in this study only one juvenile specimen was found at LEBU Beard also noted the palms Roystonea oleracea (Jacq.) O.F. Cook and Bactris major, as well as the giant reed Gynerium sagittatum (Aubl.) P. Beauv. in what he classified as Palm Swamp vegetation. These were also found along rivers in this study along with Lonchocarpus sericeus (Poir.) Kunth ex DC., Manilkara bidentata (A. DC.) A. Chev., Carapa guianensis Aubl., Virola surinamensis (Rol. ex Rottb.) Warb. and Calophyllum lucidum, which Beard, (1946) also found in Palm Swamp vegetation. Beard (1946) developed an in-depth classificat ion of all vegetation in Trinidad. Nelson (2004) provided an update in 2004. Nelson (2004) landscape level vegetation groupings approximated Beards associations. This discu ssion will focus more on Beards work, as he provided more in-depth information about indi vidual species distributi ons. Beards vegetation type for each of the study sites is shown in Table 2-13. Twenty-three sites fell in the geographic range of Evergreen Seasonal Forest characterized by the Carapa guianensis Eschweilera
56 subglandulosa association. In the absence of removal and modification of Trinidads natural vegetation, this association would cover most of the island. In this study, there were three forested (FO) sites found within the Evergr een Seasonal Forest geographic range, namely MORU, MORM and MORL. These fell specifically within the Mora faciation of Evergreen Seasonal Forest, which according to Beard (1946), consisted of almost monotypic stands of Mora excelsa Other common species listed for this faciation were C. guianensis Swartzia pinnata (Vahl) Willd. and Brownea latifolia Jacq. It was noted; however that these species were found at less than 0.16 the density of M. excelsa (Beard 1946). Beard (1946) also found Bactris major and Ischnosiphon arouma in Mora forest understorey. All of the aforementioned species were found at the Moruga sites during this project, and M. excelsa did dominate both the tree and ground flora at these sites. None of the other FO sites fell within the geographic range of Ever green Seasonal Forest; however, there appeared to be some remnan t forest species at some of the Abandoned Vegetation/Secondary Vegetation (SV) sites. For example, POOM had Brownea latifolia and POOU had Pentaclethra macroloba (Willd.) Kuntze, both common in Evergreen Seasonal Forest. These species may have been deliberatel y or accidentally retain ed during land clearing for agriculture, or have since reestablished at sites after agricultural abandonment. According to Beard (1946), most of the No rthern Range is covered in Lower Montane Forest. This forest t ype was characterized by Licania ternatensis Hook. f. ex Duss and Byrsonima spicata (Cav.) DC; however, none of these spec ies were found in this study. At the Northern Range FO site CAUM, Terminalia amazonia (J.F. Gmel.) Exell, Pouteria minutiflora (Britton) Sandwith and Hirtella racemosa Lam. were identified. Beard (1946) noted these species in Lower Montane Forest but at lower densities than L. ternatensis and B. spicata. T.
57 amazonia was also found at two SV sites in th e Northern Range. Another Lower Montane species Chimarrhis cymosa was found at the SV site NORU. Sites PENU, PENM and PENL were located in Semi Evergreen fore st, specifically, the Bravaisia faciation (Beard 1946). B eard (1946) noted the presence of the following species: Bravaisia integerrima, Brosimum alicastrum SW, Standl., Hura crepitans various Inga sp., Coccoloba venosa L., Brownea latifolia and Bursera simaruba. These were also found during field sampling for this study. Beard (1946) also found Symphonia globulifera L. f., V. surinamensis and Manicaria saccifera Gaertn. along rivers in Trinidad. S. globulifera was not found in this study, but V. surinamensis was found at POOU, CAUM and NORL. M. saccifera was found at NORU. Adams & Com eau (Unpublished) also listed V. surinamensis as a riparian species. Erythrina glauca was noted as common in lowland sw amps and along rivers in Trinidad by Feinsinger et al. (1982) and Adams & Ba ksh-Comeau (Unpublished). The latter also mentioned that E. glauca was introduced to Trinidad as a shade tree for lowland cocoa plantations and has since become naturalized and widespread along ri vers. While no supporting documentation has been found, it is commonly known that Bambusa vulgaris is abundant along rivers in Trinidad, having been planted for riverbank stabili zation (Forestry Division pers. comm.). Of the 502 morphotypes collected, not al l may be specific to riverbanks. Carapa guianensis, for instance, is a type species for Evergr een Seasonal Forest, the most common forest type in Trinidad (Beard 1946). Manilkara bidentata is abundant in Littoral Woodland along the coastline (Beard 1946). In additi on, a number of agricultu ral plants were found at the study sites, the result of human influence, rather than naturally occurri ng patterns and processes.
58 Some species found in this study were also doc umented in riparian vegetation in the Caura River Basin, Bolivar State, in neighboring Venezuela (Rosales et al. 2003). Rosales et al. (2003) noted the presence of Myrcia splendens (Sw.) DC. and Vismia sp. at the river channel margin among the group of early successional riparian plants. M. splendens was only found at POOL in this study, but it was located in the tr ansect block at the waters edge. Vismia cayennensis (Jacq.) Pers. was found at AROU in block 1, and Vismia laxiflora Reichardt was found at NORL in block 4 and ARIL in block 1. Rosales et al. (2003) also noted an abundance of ferns in the Caura River Basin, which they linked to high unde rstory humidity. In addition, Rosales et al. (2003) found an abundance of vines and reeds in both disturbed riparian areas and areas with poor drainage. In this study, vines such as Ipomea sp., Merremia umbellata (L.) Hallier f. and the reed G. sagittatum were abundant at the swampy ARIL site. Rosales et al. (2003) described a high incidence of palms like Attalea maripa (Aubl.) Mart Euterpe precatoria and Desmoncus sp. in flooded forests of the Caura River Basin. All palms were found at riparian sites in Trinidad; however, A. maripa is more associated with disturbed, fire affected areas in this c ountry (Adams & Baksh-Comeau Unpublished). Rosales et al. (2003) also found Eschweilera subglandulosa, Schefflera morototoni (Aubl.) Maguire, Steyerm. & Frodin and Virola surinamensis. All three were found in Trinidad in this study. They also noted that the riparian forest floo r along the Caura River was comp rised of the following genera: Piper sp., C ostus sp., Heliconia sp., Renealmia sp., Eugenia sp., Tabermontana sp., Miconia sp. and Psychotria sp. These were also found during this study (Appendix A). The apparent similarity in riparian flora between Trinidad and Venezuela, is in keeping with the st rong floristic affinity between Trinidad and South America (Beard 1946)
59 From the above discussion, it is evident that common forest species are also found at riparian sites. Some specimens of Brownea latifolia C. guianensis, Eschweilera subglandulosa and Pentaclethra macroloba were even found in block 1 of the transects at the waters edge. This may mean that these forest species can tolera te a wide range of cond itions, or it may be that the riparian zone in Trinidad is very narrow allo wing forest species to surv ive close to the rivers edge. Riparian Vegetation Structure Bambusa vulgaris had the highest importance value of trees sam pled. This is based largely on its high relative coverage value of 99.12%. The relative coverage values were due to the growth habit of B. vulgaris, which formed large stands where found. In the case of CAUU, there was a single cluster of 500 culms with an average DBH of 10 cm. Tectona grandis had the second highest importance value. It was only found at one site in a teak plantation but occurred there in very high numbers, as would be expected. Spondias mombin and Theobroma cacao had the 4th and 5th highest importance values of all the tree s found. All of these species are introduced to Trinidad. B. vulgaris and S. mombin are widespread and naturaliz ed in Trinidad, (Adams & Baksh-Comeau Unpublished), but th e other two species appear to be limited to areas where they are planted. The native species Cecropia peltata had the third highest importance value, and two other native species Mora excelsa and Andira inermis (W. Wright) Kunth ex DC. had the 6th and 7th highest values, respectively. The high importance value of M. excelsa was expected given its presence at sites that fall within the geographic range of the Mora faciation of Evergreen Seasonal Forest. Exotic species such as Coffea sp. and Pureraria phaseoloides dominated the ground flora. Coffea sp. had the highest relative covera ge value and was found at SV sites. P. phaseoloides is
60 an exotic species found at SV and AG sites. Generally, it appears th at exotic species are common and abundant at riparian sites in Trinida d. This will be explored further in Chapter 3. Sites with the highest levels of richness and diversity appear to be SV areas. In particular, AROM is in the early stages of regeneration, a nd it may be that open conditions and relatively high light levels promote the growth of a hi gh number of agricultura l seedlings and weedy species. This in turn yielded high richness. It has been suggested that in some cases, high richness and diversity in riparian areas may be facilitated by an abundance of exotics (Naiman et al. 2000). This may be the case in Trinidad, wh ere high species richness was found in the SV sites, which had a combination of native and introduced species. The low diversity and richness sites were mo stly agricultural areas where ground flora is heavily managed or removed. Sugarcane sites SOUU and SOUM were burnt as part of the harvesting process, and when the sites were sa mpled, regeneration of sugarcane and weeds had just begun. Even sites where sugarcane was not bu rnt, there was low richness and diversity due to the dominance of sugarcane. In the case of CU MM, the ground flora largely consisted of lawn grass ( Axonopus compressus ) which appeared to be regularly mowed. Riparian Zone Delineation Naim an et al. (2005) defined the riparian zone as the area extending from the waters edge to areas beyond the bank that either experience flooding or have elevated soil water levels. In this study vegetation was surveyed at each site along 50 m transects running from the waters edge perpendicular to th e river channel. A 50 m vegetation transect length was used as this encompassed and exceeded the width of the flooded areas observed during pr eliminary site visits during the rainy seasons of 2005 and 2006. While 50 m was the initial conservative estimate of riparian zone width, a revised width of 30 m is suggested for Trinidad based on riparian z one delineation factors such as height relative
61 to surface water level, stream si ze, location in the watershed, and evidence of frequent erosion and deposition along the riverbanks as suggested by Naiman et al. (2005) and Drucker et al. (2008). While riparian zone width varied from site to site depending on the aforementioned factors, a 30 m cutoff included the range of possible riparian zone wi dths in Trinidad from small, narrow rivers in upper reaches to large wide rivers in lower reaches. The 30 m cutoff eliminated sample blocks 6 m above the channel margin, which were unlikely to be flooded or have elevated water tables even during higher discharges in the ra iny season. Naiman et al. (2005) also suggested that the presence of wetland he rbaceous flora was a good delineator of riparian zones. While this is the first in-depth study of riparian vegeta tion of Trinidad, a 30 m riparian zone included plants noted in Adams & BakshComeau (Unpublished), as common along rivers and wetlands in Trinidad. Riparian vegetation buffers are used in managi ng river water quality as explained earlier in this chapter. Mean riparian buffer width in th e United States for streams >5 m wide was 28.1 m and the equivalent in Canada was 43.8 m (Lee & Smyth 2004). For streams less than or equal to 5 m in width the mean riparian buffer widt h was 21.8 m and 29.6 m for the United States and Canada, respectively (Lee & Smyth 2004). Wenger (1999) advocated a 30 m buffer as a good rule of thumb for riparian buffers for sediment retention. While there has been much work on determining suitable riparian buffer widths for ri ver water quality, more recently researchers are focusing on protecting active river areas includi ng riparian zones as part of overall river management schemes (Smith & Schiff 2008). For Trinidad this will include the 30 m riparian zone delineated Summary The baseline data in this chapter help fill the information gap on Caribbean island riparian zones. In general, riparian trends from resear ch in North America, Europe and South America
62 appear relevant to small islands like Trinida d. For example, high plan t biodiversity and a prevalence of exotic species were noted in this study. Trinidad riparian zones are environmentally heterogenous and heavily impact ed by anthropogenic infl uences as is the general pattern. It may be that anthropogenic influences are even more pronounced on small island settings due to limited land area. This study also recognizes a ripari an zone width of 30 m for Trinidad, which can be used as the basis fo r establishing riparian buffers or active river areas.
63Table 2-1. Rivers used in the study Ecoregion Level of human impact (based on 1994 land use data) Geomorphological area Catchment /River Catchment forest cover in 1994 (%) Catchment forest cover in 2001 (%) Northern Range Arouca 34 51 Central Plain Couva 17 22 High (<40% forest cover) Southern Plain South Oropouche 31 39 Northern Range Caura 66 73 Central Plain Caparo 43 51 Dry Low (>40% forest cover) Southern Plain Penal (Grande Riviere River) 63 72 Northern Range Aripo 54 66 Central Plain Cumuto 48 84 High (<60% forest cover) Southern Plain Poole 53 77 Northern Range North Oropouche 75 95 Central Plain Lebranche 62 86 Wet Low (>60% forest cover) Southern Plain Moruga 84 91
64 Table 2-2. Environmental and anthropogenic data collected Variable category Variable type Variable Anthropogenic Metric Percentage forest cover in watershed (1994 and 2001 data) Anthropogenic Metric Distance from sample point to nearest paved road Anthropogenic Categorical Land ownership: private vs. public Anthropogenic Categorical Presence/absence of recreational activities Anthropogenic Categorical Presence/absence of fire Anthropogenic Categorical Presence/abse nce of cultural/religious activities Anthropogenic Categorical Major land cover per reach Anthropogenic Categorical Presence/absence of drainage works, for example, channelization or dredging Anthropogenic Categorical Presence/abse nce of surface water abstraction. Anthropogenic Categorical Presence/absence of groundwater abstraction. Anthropogenic Categorical Presence/absence of maintenance, for example, clearing of the sides of the roads Anthropogenic Categorical Evidence of pollution Anthropogenic Categorical Land c over per 10 x 10 m transect block Hydrological Metric Mean bankfull depth Hydrological Metric Mean riverbank slope Hydrological Metric Mean channel width Hydrological Metric Mean bankfull width Hydrological Metric Mean river velocity Hydrological Metric Mean river discharge Terrestrial Metric Catchment length Terrestrial Metric Catchment shape Terrestrial Metric Catchment relief Terrestrial Metric Catchment area Terrestrial Categorical Major soil type Terrestrial Metric Elevation above sea level Terrestrial Categorical Evidence of braiding Terrestrial Categorical Evidence of meandering Terrestrial Categorical Presence/absence of animal activities Terrestrial Metric Distance of sample point from waters edge Terrestrial Metric Riverbank length Terrestrial Metric Elevation above water margin Terrestrial Metric Slope Terrestrial Metric Canopy closure Terrestrial Metric Soil organic carbon content (0-30 cm and 30-60 cm) Terrestrial Metric Soil total n itrogen (0-30 cm and 30-60 cm) Terrestrial Metric Soil plant available phosphates (0-30 cm and 30-60 cm) Terrestrial Metric Soil calcium (0-30 cm and 30-60 cm) Terrestrial Metric Soil potassium (0-30 cm and 30-60 cm) Terrestrial Metric Soil particle size (% sand, silt, clay and gravel) (0-30 cm only) Terrestrial Metric Soil electroconductivity (EC) (0-30 cm and 30-60 cm) Terrestrial Metric Soil magnesium (0-30 cm and 30-60 cm)
65Table 2-3. Summary of block a nd site level metric data Maximum Minimum Mean Elevation above sea level (m) 228.60 2.30 46.30 Discharge (m3) 6.42 0.00 0.48 Bank slope -14.00 -50.67 -28.85 Channel width (m) 24.36 1.79 5.99 Bankfull width (m) 31.67 5.20 15.97 Bankfull length (m) 2535.33 143.33 730.78 Bankfull depth (m) 11.29 0.84 3.91 Canopy closure (%) 100.00 0.16 59.28 Cumulative elevation (m) 26.10 -2.79 5.32 Slope 29.00 -57.00 -8.47 Distance from paved roads (m) 3000.00 5.00 403.14 Soil pH (30 cm) 8.19 3.81 5.76 Soil nitrogen (30 cm) (g kg-1) 36.00 0.20 4.67 Soil phosphates (30 cm) (mg kg-1) 151.00 1.00 11.73 Soil potassium (30 cm) (c mol kg-1) 0.21 0.01 0.04 Soil calcium (30 cm) (c mol kg-1) 26.01 0.32 7.55 Soil magnesium (30 cm) (c mol kg-1) 7.79 0.04 2.11 Soil electroconductivity (30 cm) (mS cm-1) 9.60 0.06 0.34 Soil organic carbon (30 cm) (g kg-1) 89.00 0.00 26.48 Soil pH (60 cm) 8.11 3.94 5.63 Soil nitrogen (60 cm) (g kg-1) 23.00 0.10 3.46 Soil phosphates (60 cm) (mg kg-1) 78.00 1.00 8.88 Soil potassium (60 cm) (c mol kg-1) 0.15 0.01 0.03 Soil calcium (60 cm) (c mol kg-1) 26.69 0.04 6.26 Soil magnesium (60 cm) (c mol kg-1) 8.34 0.03 1.90 Soil electroconductivity (60 cm) (mS cm-1) 7.85 0.01 0.25 Soil organic carbon (60 cm) (g kg-1) 48.00 0.00 16.98 Soil% clay 66.68 1.30 20.63 Soil% sand 83.97 3.10 38.86 Soil% silt 70.72 0.90 37.36 Soil% gravel 63.98 0.00 3.15
66 Table 2-4. Summary of site level categorical data Site Land use Land use 50 -100 m Land ownership Hunting/ recreation activities Cultural/ religious activities Human modification of channel Surface water Abstraction Maintenance activities PollutionAnimals Fire ARIL GR FO PU Y N N N N N N N ARIM AG AG PR Y N Y Y N Y Y N ARIU FO AG PR Y N Y N N Y N N AROL GR DE PR N N Y N Y Y N N AROM SV SV PR Y N N N N Y N N AROU SV SV PR Y N N N N Y N N CAPL GR AG PU N N Y N N Y N Y CAPM SV GR PR Y N Y N N Y Y Y CAPU AG AG PR N N Y N N Y N Y CAUL DE DE PU Y N Y N N Y N Y CAUM FO FO PR Y N N N N Y N N CAUU SV SV PU Y N N N N N N N COUL FO AG PU N N N N N Y N Y COUM SV DE PR N N N N N Y N Y COUU SV SV PR Y N N N N Y N N CUML SV SV PR N N N N N N Y N CUMM AG AG PR N N Y N N N N N CUMU AG AG PR N N N N N N N N LEBL SV SV PR N N N N Y Y N N LEBM SV SV PR N N N N N Y N N LEBU SV SV PR N N N N N N Y N ARI=Aripo, ARO=Arouca, CAP=Caparo, CAU=Caura, CUM=Cumuto, COU= Couva, LEB=Lebranche, MOR=Moruga, NOR=North Oropouche, PEN=Pena l, POO=Poole, S OU=South Oropouche, L=Lower Reach, M=Mi ddle Reach, U=Upper Reach. DE=Developed (Buildings, roads, playgrounds prese nt. Site may be landscaped.), SV=Secondary Vegetation (Evidence of past or present land conversion. Trees and remnant agricultural species may be present. No sign of active maintenance of the site), FO=Forest (No past or present human driven land conversion evident. Both trees and ground flora prese nt. Natural bodies of water, for example, ponds may also be present), Ag=Agriculture (Agricultural crops present, active maintenance of site, for example, lawn mowing or weeding), GR=Grassland (No trees, no agriculture. Some ground cover present. No site maintenance, for example, lawn mowing evident). Y=Y es, N=No, PU=Public, PR=Private,
67 Table 2-4. Continued Site Land use Land use 50 -100 m Land ownership Hunting/ recreation activities Cultural/ religious activities Human modification of channel Surface water abstraction Maintenance activities PollutionAnimals Fire MORL FO FO PU Y N N N N N N N MORM FO FO PU Y N N N N N N N MORU FO FO PU Y N N N N N N N N ORL SV AG PR Y N Y N N Y Y N N ORM GR GR PR N N N N N Y N Y N ORU FO FO PR Y N N N N N N N PENL FO FO PU Y N N N N N N N PENM FO FO PU Y N N N N N N Y PENU AG AG PU Y N N N N N N Y POOL SV FO PR Y N N N N Y Y N POOM SV SV PR Y N N N N N Y N POOU SV SV PR N N N N N Y Y Y SOUL SV DE PR Y N Y N N Y Y Y SOUM AG DE PR N N Y N N Y N Y SOUU AG AG PR N N N N N Y N Y ARI=Aripo, ARO=Arouca, CAP=Caparo, CAU=Caura, CUM=Cumuto, COU= Couva, LEB=Lebranche, MOR=Moruga, NOR=North Oropouche, PEN=Pena l, POO=Poole, S OU=South Oropouche, L=Lower Reach, M=Mi ddle Reach, U=Upper Reach. DE=Developed (Buildings, roads, playgrounds prese nt. Site may be landscaped.), SV=Secondary Vegetation (Evidence of past or present land conversion. Trees and remnant agricultural species may be present. No sign of active maintenance of the site), FO=Forest (No past or present human driven land conversion evident. Both trees and ground flora prese nt. Natural bodies of water, for example, ponds may also be present), Ag=Agriculture (Agricultural crops present, active maintenance of site, for example, lawn mowing or weeding), GR=Grassland (No trees, no agriculture. Some grond cover present. No site maintenance, for example, lawn mowing evident). Y=Ye s, N=No, PU=Public, PR=Private
68Table 2-5. Catchment characteristics Catchment Maximum basin relief (m) Catchment length (km) Relief ratio (height/ length) Area (km2) Form factor (area/length2) % forest cover (1994) % forest cover (2001) Aripo 787.40 14.39 0.055 52.68 0.25 53.85 66.19 Arouca 647.97 14.77 0.044 59.40 0.27 34.24 50.60 Caparo 73.15 24.07 0.003 96.72 0.17 43.24 50.90 Caura 647.97 14.06 0.046 48.49 0.25 65.85 72.80 Couva 88.39 18.52 0.005 193.32 0.56 16.51 22.20 Cumuto 85.34 17.47 0.005 86.57 0.28 47.75 83.60 L'ebranche 68.00 9.36 0.007 47.09 0.54 62.49 85.50 Moruga 245.67 18.32 0.013 237.36 0.71 83.82 90.60 North Oropouche 647.97 20.61 0.031 139.37 0.33 75.37 94.86 Penal 245.67 6.62 0.037 80.35 1.83 62.84 72.00 Poole 68.00 32.70 0.002 188.24 0.18 52.72 76.70 South Oropouche 162.73 25.07 0.006 438.67 0.70 30.60 38.87
69Table 2-6. Relative Coverage, Density, Frequency and Impo rtance Value (IV) of the Tree Species at all 36 sites Species Relative coverage (%) Relative density (%) Relative frequency (%) IV (%) Bambusa vulgaris Schrad. ex J.C. Wendl. 99.12 6.51 4.62 110.25 Tectona grandis L. f. 0.04 9.30 0.31 9.65 Cecropia peltata L. 0.02 4.42 4.31 8.75 Theobroma cacao L. 0.01 5.47 2.46 7.94 Spondias mombin L. 0.07 2.91 4.00 6.98 Mora excelsa Benth. 0.07 5.12 0.92 6.11 Andira inermis (W. Wright) Kunth ex DC. 0.03 2.56 1.85 4.43 Swartzia pinnata (Vahl) Willd. 0.02 2.79 1.54 4.35 Inga ingoides (Rich.) Willd. 0.01 2.09 1.85 3.95 Citrus sp. 0.00 1.86 1.85 3.71 Erythrina poeppigiana (Walp.) O.F. Cook 0.06 1.74 1.85 3.65 Erythrina glauca Willd. 0.02 1.16 1.85 3.03 Lonchocarpus sericeus (Poir.) Kunth ex DC. 0.02 1.16 1.85 3.03 Syzygium malaccense (L.) Merr. & L.M. Perry 0.01 1.28 1.54 2.82 Cordia collococca L. 0.01 1.51 1.23 2.75 Lonchocarpus heptaphyllus (Poir.) DC. 0.01 1.74 0.92 2.68 Hura crepitans L. 0.01 1.16 1.23 2.41 Guazuma ulmifolia Lam. 0.01 1.40 0.92 2.33 Brownea latifolia Jacq. 0.00 1.05 1.23 2.28 Musa sp. 0.00 1.63 0.62 2.25 Brosimum alicastrum SW. 0.00 0.93 1.23 2.16 Syzygium cumini (L.) Skeels 0.08 1.16 0.92 2.16 Only species with an importance value greater than 1% are list ed. Species are listed in order of descending IV
70Table 2-6. Continued Species Relative coverage (%) Relative density (%) Relative frequency (%) IV (%) Attalea maripa (Aubl.) Mart. 0.01 0.81 1.23 2.05 Cupania americana L. 0.00 0.81 1.23 2.05 Ochroma pyramidale (Cav. ex Lam.) Urb. 0.00 0.81 1.23 2.05 Bravaisia integerrima (Spreng.) Standl. 0.03 1.05 0.92 2.00 Schefflera morototoni (Aubl.) Maguire, Steyerm. & Frodin 0.01 1.05 0.92 1.98 Sabal mauritiiformis (H. Karst.) Griseb. & H. Wendl. 0.00 1.05 0.92 1.97 Eschweilera subglandulosa (Steud. ex O. Berg) Miers 0.00 1.05 0.92 1.97 Casearia guianensis (Aubl.) Urb. 0.00 0.70 1.23 1.93 Roystonea oleracea (Jacq.) O.F. Cook 0.01 0.81 0.92 1.75 Mangifera indica L. 0.01 0.81 0.92 1.75 Sterculia pruriens (Aubl.) K. Schum. 0.01 0.81 0.92 1.74 Artocarpus altilis (Parkinson) Fosberg 0.01 0.81 0.92 1.74 Guarea guidonia (L.) Sleumer 0.00 0.70 0.92 1.63 Carica papaya L. 0.00 1.28 0.31 1.59 Ficus maxima Mill. 0.01 0.58 0.92 1.52 Castilla elastica Sess ex Cerv. 0.00 0.58 0.92 1.51 Pisonia cuspidata Heimerl 0.01 1.16 0.31 1.48 Pachira insignis (Sw.) Sw. ex Savigny 0.01 0.81 0.62 1.44 Genipa americana L. 0.01 0.47 0.92 1.39 Chrysophyllum cainito L. 0.01 0.70 0.62 1.33 Rollinia exsucca (DC. ex Dunal) A. DC. 0.00 0.35 0.92 1.28 Zanthoxylum sp. 0.00 0.35 0.92 1.27 Only species with an importance value greater than 1% are list ed. Species are listed in order of descending IV
71Table 2-6. Continued Species Relative coverage (%) Relative density (%) Relative frequency (%) IV (%) Chrysophyllum argenteum Jacq. 0.00 0.35 0.92 1.27 Ficus broadwayi Urb. 0.00 0.58 0.62 1.20 Terminalia amazonia (J.F. Gmel.) Exell 0.00 0.58 0.62 1.20 Eugenia procera (Sw.) Poir. 0.00 0.58 0.62 1.20 Dipteryx odorata (Aubl.) Willd. 0.01 0.47 0.62 1.09 Virola surinamensis (Rol. ex Rottb.) Warb. 0.00 0.47 0.62 1.08 Carapa guianensis Aubl. 0.00 0.47 0.62 1.08 Swietenia macrophylla King 0.00 0.70 0.31 1.01 Only species with an importance value greater than 1% are list ed. Species are listed in order of descending IV
72 Table 2-7. Species with the 20 highest relative coverage va lues in the ground flora. Species Relative coverage (%) Coffea sp. 5.21 Selaginella plana (Desv. ex Poir.) Hieron. 3.46 Justicia secunda Vahl 3.44 Pueraria phaseoloides (Roxb.) Benth. 3.44 Heliconia bihai or spatho-circinada 3.39 Saccharum officinarum L. 3.16 Axonopus compressus (Sw.) P. Beauv. 3.00 Paspalum fasciculatum Willd. ex Flgg 2.92 Mora excelsa Benth. 2.87 Costus scaber Ruiz & Pav. 2.27 Flemingia strobilifera (L.) R. Br. 2.12 Poaceae 2.10 Bactris major Jacq. 1.89 Scleria melaleuca Rchb. ex Schltdl. & Cham. 1.77 Sorghum sp. 1.55 Pachystachys coccinea (Aubl.) Nees 1.54 Dieffenbachia seguine (Jacq.) Schott 1.48 Blechum pyramidatum (Lam.) Urb. 1.21 Bambusa vulgaris Schrad. ex J.C. Wendl. 1.04 Cynodon dactylon (L.) Pers. 0.93
73Table 2-8. Diversity, species richness, most important tree species and hi ghest percentage cover ground flora species Site S H'(loge) Highest tree importance value Highest percentage cover ground flora species ARIL 36 3.09 Erythrina glauca Willd. Ipomea sp. ARIM 54 3.72 Carica papaya L. Parthenium hysterophorus L. ARIU 36 3.30 Erythrina poeppigiana (Walp.) O.F. Cook Selaginella plana (Desv. ex Poir.) Hieron AROL 27 3.08 N o trees Sorghum sp. AROM 64 3.79 Mangifera indica L. Scleria melaleuca Rchb. ex Schltdl. & Cham. AROU 42 3.29 Cecropia peltata L. P achystachys coccinea (Aubl.) Nees CAPL 20 2.71 N o trees Poaceae CAPM 26 2.90 Syzygium cumini (L.) Skeels F lemingia strobilifera (L.) R. Br. CAPU 26 2.86 B ambusa vulgaris Schrad. ex J.C. Wendl Saccharum officinarum L. CAUL 13 2.37 B ambusa vulgaris Schrad. ex J.C. Wendl A xonopus compressus (Sw.) P. Beauv. CAUM 52 3.67 B ambusa vulgaris Schrad. ex J.C. Wendl Attalea maripa (Aubl.) Mart. CAUU 35 3.26 B ambusa vulgaris Schrad. ex J.C. Wendl Selaginella plana (Desv. ex Poir.) Hieron. COUL 20 2.55 B ambusa vulgaris Schrad. ex J.C. Wendl F lemingia strobilifera (L.) R. Br. COUM 36 3.32 B ambusa vulgaris Schrad. ex J.C. Wendl F lemingia strobilifera (L.) R. Br. COUU 34 3.15 B ambusa vulgaris Schrad. ex J.C. Wendl P ueraria phaseoloides (Roxb.) Benth. CUML 43 3.44 B ambusa vulgaris Schrad. ex J.C. Wendl J usticia secunda Vahl CUMM 15 2.28 Citrus sp. Axonopus compressus (Sw.) P. Beauv. CUMU 41 3.56 B ambusa vulgaris Schrad. ex J.C. Wendl J usticia secunda Vahl LEBL 43 3.57 B ambusa vulgaris Schrad. ex J.C. Wendl H eliconia bihai or spatho-circinada LEBM 28 2.90 B ambusa vulgaris Schrad. ex J.C. Wendl H eliconia bihai or spatho-circinada LEBU 58 3.80 Ficus maxima Mill. Costus scaber Ruiz & Pav. MORL 47 3.43 Mora excelsa Benth. L eptochloa sp. MORM 33 2.83 Mora excelsa Benth. Mora excelsa Benth. MORU 32 2.80 Mora excelsa Benth. Mora excelsa Benth. NORL 48 3.66 B ambusa vulgaris Schrad. ex J.C. Wendl P ueraria phaseoloides (Roxb.) Benth. NORM 31 3.20 B ambusa vulgaris Schrad. ex J.C. Wendl P anicum maximum Jacq. ARI=Aripo, ARO=Arouca, CAP=Caparo, CAU=Caura, CUM=Cumuto, COU=Couva, LEB=Lebranch e, MOR=Moruga, NOR=North Oropouche, PEN=Penal, POO=Poole, SOU=South Oropouche, L=Lowe r Reach, M=Middle Reach, U=Upper Reach S=species richness H'(loge)= Diversity
74Table 2-8. Continued Site S H'(loge) Highest tree importance value Highest percentage cover ground flora species NORU 60 3.89 Hieronyma laxiflora (Tul.) Mll. Arg. Coffea sp. PENL 37 3.25 Bravaisia integerrima (Spreng.) Standl. P aullinia leiocarpa Griseb. PENM 40 3.42 Bravaisia integerrima (Spreng.) Standl. B actris major Jacq. PENU 13 1.15 Tectona grandis L. f. B actris major Jacq. POOL 46 3.60 Erythrina poeppigiana (Walp.) O.F. Cook Coffea sp. POOM 38 3.29 Bambusa vulgaris Schrad. ex J.C. Wendl. H eliconia bihai or spatho-circinada POOU 43 3.42 Pisonia cuspidata Heimerl Coffea sp. SOUL 30 3.16 Bambusa vulgaris Schrad. ex J.C. Wendl. Saccharum officinarum L. SOUM 8 1.48 Erythrina glauca Willd. Acroceras zizanioides (Kunth) Dandy SOUU 14 2.10 Sapindus saponaria L. Saccharum officinarum L. ARI=Aripo, ARO=Arouca, CAP=Caparo, CAU=Caura, CUM=Cumuto, COU=Couva, LEB=Lebranch e, MOR=Moruga, NOR=North Oropouche, PEN=Penal, POO=Poole, SOU=South Oropouche, L=Lowe r Reach, M=Middle Reach, U=Upper Reach S=species richness H'(loge)= Diversity
75 Table 2-9. Catchment species ri chness (trees and ground flora) Dry Ecoregion Wet Ecoregion Low Impact High Impact Low Impact High Impact Geomorphological Unit North 93 (Caura) 117 (Arouca) 123 (North Oropouche) 106 (Aripo) Central 69 (Caparo) 62 (Couva) 93 (Lebranche) 83 (Cumuto) South 73 (Penal) 43 (South Oropouche ) 95 (Moruga) 100 (Poole) Table 2-10. Catchment species di versity (trees and ground flora). Dry Ecoregion Wet Ecoregion Low Impact High Impact Low Impact High Impact Geomorphological Unit North 4.23 (Caura) 4.37 (Arouca) 4.56 (North Oropouche) 4.29 (Aripo) Central 3.72 (Caparo) 3.68 (Couva) 4.05 (Lebranche) 4.02 (Cumuto) South 3.35 (Penal) 3.16 (South Oropouc he) 3.68 (Moruga) 4.16 (Poole) Table 2-11. Richness and diversity by Geomorphological Unit, Ecoregion and Level of catchment human impact Species richness Species diversity North Geomorphological Unit 292 5.20 Central Unit 209 4.72 South Unit 228 4.66 Dry Ecoregion 314 5.02 Wet Ecoregion 351 5.18 High human impact 337 5.17 Low human impact 323 5.04
76 Table 2-12. Species found in this study, wh ich are known to be associated with rivers or swamps according to Adams & Baksh-Comeau (Unpublished) Species Mimosa pigra L. Pterolepis glomerata (Rottb.) Miq. Combretum fruticosum (Loefl.) Stuntz Lomariopsis japurensis (Mart.) J.Sm. Acroceras zizanioides (Kunth) Dandy Calathea lutea Schult. Commelina diffusa Burm. f. Commelina erecta L. Cyclanthus bipartitus Poit Cyperus luzulae (L.) Rottb. ex Retz. Cyperus surinamensis Rottb. Dichanthium caricosum (L.) A. Camus Faramea occidentalis (L.) A. Rich Gynerium sagittatum (Aubl.) P. Beauv. Heliconia bihai (L.) L. Hymenachne amplexicaulis (Rudge) Nees Hymenocallis tubiflora Salisb. Hypoderris brownii J.Sm. Isertia parviflora Vahl Justicia comata (L.) Lam. Leptochloa ?longa Pachystachys coccinea (Aubl.) Nees Palicourea crocea (Sw.) Roem. & Schult. Panicum ?frondescens Paspalum fasciculatum Willd. ex Flgg Pennisetum purpureum Schumach.
77Table 2-12. Continued Species Pharus latifolius L. Phenax sonneratii (Poir.) Wedd. Piper ?hispidum Piper hispidum Sw. Piresia sympodica (Dll) Swallen Psychotria capitata Ruiz & Pav. Renealmia alpinia (Rottb.) Maas Spathiphyllum cannifolium Schott. Thelypteris serrata (Cav.) Alston Urochloa mutica (Forssk.) T.Q. Nguyen Carapa guianensis Aubl. Ficus yaponensis Desv Lonchocarpus heptaphyllus (Poir.) DC. Lonchocarpus sericeus (Poir.) Kunth ex DC. Manilkara bidentata (A. DC.) A. Chev. Mouriri rhizophorifolia (DC.) Triana Pterocarpus officinalis Jacq. Quiina cruegeriana Griseb. Sapindus saponaria L. Spondias mombin L. Virola surinamensis (Rol. ex Rottb.) Warb. Vismia cayennensis (Jacq.) Pers. Bactris major Jacq. Cnemidaria ?spectabilis Lasiacis ligulata Hitchc. & Chase Sphenoclea zeylanica Gaertn Tripogandra serrulata (Vahl) Handlos
78Table 2-13. General vegetation classificati on of the sites used in the study according to Beard (1946) and Nelson (2004) Site Beards forest type Nelsons landscape tier unit ARIL Evergreen Seasonal Forest Evergreen Seasonal ARIM Lower Montane Rain Forest Lower Montane ARIU Lower Montane Rain Forest Lower Montane AROL Semi-evergreen Seasonal Forest Semi Evergreen Seasonal AROM Lower Montane Rain Forest Lower Montane AROU Lower Montane Rain Forest Lower Montane CAPL Evergreen Seasonal Forest Evergreen Seasonal CAPM Evergreen Seasonal Forest Evergreen Seasonal CAPU Evergreen Seasonal Forest Evergreen Seasonal CAUL Evergreen Seasonal Forest Semi Evergreen Seasonal CAUM Lower Montane Rain Forest Lower Montane CAUU Lower Montane Rain Forest Lower Montane COUL Evergreen Seasonal Forest Evergreen Seasonal COUM Evergreen Seasonal Forest Evergreen Seasonal COUU Evergreen Seasonal Forest Evergreen Seasonal CUML Evergreen Seasonal Forest Evergreen Seasonal CUMM Evergreen Seasonal Forest Evergreen Seasonal CUMU Evergreen Seasonal Forest Evergreen Seasonal LEBL Evergreen Seasonal Forest Evergreen Seasonal LEBM Evergreen Seasonal Forest Evergreen Seasonal LEBU Evergreen Seasonal Forest Evergreen Seasonal MORL Evergreen Seasonal Forest-Mora faciation Evergreen Seasonal MORM Evergreen Seasonal Forest-Mora faciation Evergreen Seasonal MORU Evergreen Seasonal Forest-Mora faciation Evergreen Seasonal NORL Evergreen seasonal Forest ARI=Aripo, ARO=Arouca, CAP=Caparo, CAU=Caura, CUM=Cumuto, COU=Couva, LEB=Lebranch e, MOR=Moruga, NOR=North Oropouche, PEN=Penal, POO=Poole, SOU=South Oropouche L=Lower Reach, M=Middle Reach, U=Upper Reach
79Table 2-13. Continued Site Beards forest type Nelsons landscape tier unit NORM Evergreen seasonal Forest Evergreen Seasonal NORU Lower Montane Rain Forest Lower Montane PENL SemiEvergreen Seasonal Forest-Bravasia faciation Semi Evergreen Seasonal PENM SemiEvergreen Seasonal Forest-Bravasia faciation Semi Evergreen Seasonal PENU SemiEvergreen Seasonal Forest-Bravasia faciation Semi Evergreen Seasonal POOL Evergreen Seasonal Forest Evergreen Seasonal POOM Evergreen Seasonal Forest Evergreen Seasonal POOU Evergreen Seasonal Forest Evergreen Seasonal SOUL Evergreen Seasonal Forest Evergreen Seasonal SOUM Evergreen Seasonal Forest Evergreen Seasonal SOUU Evergreen Seasonal Forest Evergreen Seasonal ARI=Aripo, ARO=Arouca, CAP=Caparo, CAU=Caura, CUM=Cumuto, COU=Couva, LEB=Lebranch e, MOR=Moruga, NOR=North Oropouche, PEN=Penal, POO=Poole, SOU=South Oropouche L=Lower Reach, M=Middle Reach, U=Upper Reach
80 Figure 2-1. Trinidad, Republic of Trinidad and Tobago
81 Figure 2-2. Geomorophological regions in Trinidad.
82 Figure 2-3. Trinidad Ecoregion Cl assification. Reprinted by perm ission from Nelson, H. P. 2004. Tropical forest ecosystems of Trinidad: Ecological pattern s and public perceptions. Ph.D. (Figure 4 page 94). Thesis University of Wisconsin, Madison, WI, US.
83 Figure 2-4. Rivers and watersheds
84 Figure 2-5 Watershed forest cover
85 Figure 2-6. Site locations
86 2 x 2 m ground flora quadrats 10 x 10 m tree sampling blocks Figure 2-7. Location and dimensions of transects and qua drats at each site (Dia gram not drawn to scale) 50 m transect 2m 2m 10m 10m 50m 50m River
87 CHAPTER 3 RIPARIAN VEGETATION GROUPS AN D DE TERMINANTS IN TRINIDAD Introduction Riparian vegetation is shaped by hydrological terrestrial, geom orphol ogical, biological, and anthropogenic factors. These parameters influence species composition, abundance, plant distribution, health and life histor y. They can also create distinct riparian groups often typified by one or more indicator species (Roberts & Ludwig 1991; Veneklaas 2005). Hydrological factors, in part icular flooding frequency, durati on, timing and spatial extent are among the most important factors controlling riparian vegetation (Tabacchi et al. 1998; Bendix & Hupp 2000). Flooding regimes directly in fluence riparian plant germination and dispersal, but also indirectly affect plants through sediment deposition or creation of anaerobic soil conditions (Gregory et al. 1991; Petit & Froe nd 2001; Gergel et al. 2002). Other relevant hydrological factors include rive r discharge and current veloci ty, which can affect species richness and distribution within the riparian zone (Naiman & Decamps 1997; Baattrup-Pedersen et al. 2005). Hydrological effects are tempered by geomor phological factors. For example, in steep valleys that typify upper watershed reaches, ripa rian zones are narrow and linear due to limited flooding. In middle and lower reaches, gentler to pography gives rise to more flooding, wider riparian zones and a different comp lement of riparian plants (Tab acchi et al. 1998; Turner et al. 2004). On a fine scale, flooding effects are modified by riparian zone geomorphology like elevation, slope and distance from bank (Turner et al. 2004; Baattrup-Peder sen et al. 2005). On a coarser geomorphological scale, watershed shape, length, and area control sediment delivery and surface runoff to the riparian zone (Gregory & Walling 1973), in turn modifying riparian vegetation characteristics (Naiman et al. 2005). Watershed surface runoff and resulting sediment
88 delivery also depend on climatic regimes. Furtherm ore, climate controls temperature, available soil moisture, and ultimately riparian plants (Williams & Wiser 2004; Lite et al. 2005). Biological elements are also determinants of riparian vegetation. For example, animals affect vegetation by dispersal, herbivory and habita t modification (Tabacchi et al. 1998). Plants also influence each other through competition an d disease (Dahm et al. 2002). Native riparian plants are often out-competed by ex otics that are suited to high di sturbance conditions in riparian areas (National Research Council 2002). Anthropogenic factors can also have substantia l effects on riparian fl ora. Riparian zone plants may be removed for agriculture or sett lement. Land use both within and upland of the riparian zone are noted determinants of ripari an vegetation (Petersen 1992; Stanley 2001; Gergel et al. 2002). Vegetation may be modified by recreational activiti es, pollution, fire, channelization or levee construction in the ri parian zone (National Research Council 2002). Dam construction can lead to inundation of riparian zones in the immediate area, but water and sediment starvation downstream. Riparian zone activities also differ based on land ownership. Jansen & Roberston (2001) noted the prevalence of grazing on private ri parian land compared to public land in Australia with subsequent impacts on vegetation. Watershed level anthropogenic variables ar e also important. For example, increased urbanization on steep slopes can alter the timing and volume of surface runoff. This can lead to riparian vegetation changes as the water flows in to the river (National Re search Council 2002). The arrangement of land use types in the watershed is also relevant. Urban or forest area configuration affects sedi ment and water delivery to the riparian zone (Burel & Baudry 2003) with subs equent changes in riparian vegetation (Allan & Johnson 1997;
89 Burel & Baudry 2003). On a smaller scale vegeta tion can differ depending on riparian vegetation patch sizes, shapes and arrangement (Freem an et al. 2003; Turner et al. 2004). As demonstrated above, factors affecting riparian vegetation can exert their effects at different scales. Feld an d Hering (2007) use the terms micro, meso, macro and mega to describe different levels of variables affecting aquatic i nvertebrates. These terms can also be applied to variables affecting riparian vegetation. Soil nutrien ts and light are micro scale variables operating within small areas of the riparian zone (Chen et al. 1999; Turn er et al. 2004). Light levels, in particular, are key determinants of ground flora patterns (Naiman & Decamps 1997). River discharge, flooding regime, channel width or overall soil type can affect the entire riparian reach at the meso level (Naiman & Decamps 1997; Robertson & Augspurger 1999). Braiding, seen at the meso scale, is associated with low riparian plant diversity, while meandering is associated with high diversity (Naiman et al. 2005). Dominant land use within the watershed, watershed size or shape can be considered coar se, macro scale factors (Baker 1989). Climate and geomorphology exert their effect at the coarsest level or mega scale. Variables are often linked across scales (Baker 1989). For example, larger catchments often have rivers with greater flooding magnitudes (Naiman et al. 2005). The study of the structure and composition, grouping and determinants of riparian vegetation allows for better understanding of ripari an systems. In turn, th is facilitates maximal use of riparian zone functions and properties, for example, as water quality buffers (Naiman & Decamps 1997), and wildlife corridors (Tabacchi et al. 1998). It also allows for informed manipulation of environmental and anthropogenic factors for riparian re storation if needed. Determining the scale at which in fluencing variables operate, sugge sts where, and what level of
90 restoration is required. Pinpointing vegetation indicat or species can aid in rapid identification of riparian groups and expedite designation of areas for restoration and conservation. Baseline information on riparian systems in Tr inidad was provided in Chapter 2. Riparian vegetation structure and composition were desc ribed for 12 rivers on the island along with concurrent environmental and anthropogenic ch aracteristics. Baseline data indicated a high degree of human interference, as riparian zone modification through agriculture, urbanization, dredging, recreation and fire was evident. Of 36 sites studied across the island, 15 were located in abandoned agricultural estates, and seven sites were in active agricultural fields. It is likely that, given the level of human activity encountered, anthropogenic variables play a greater role in shaping riparian vegetation in Trinidad than hydrological, geomorphological or biological variables. This chapter analyses the baseline riparian data to identify vegetation groups across the island and determine their indicator species. It al so identifies the most significant variables affecting the composition and distribution of the groups, determines the most important scale at which these variables operate a nd test the hypothesis that hu man intervention most heavily influences the composition and distribution of riparian vegetation groups in Trinidad. Methods Data Collection and Scaling Data were collected on vegetation, environm en tal and anthropogenic variables along three, 30 m transects at 36 sites in Tr inidad. Ground flora percentage cover and tree basal area were recorded within 10 m2 blocks along each transect. Envir onmental and anthropogenic data were collected for 54 variables at four scales, na mely the micro, meso, macro and mega scales following Feld & Hering (2007) seen in Table 3-1. Micro scale variable s (the finest scale) include soil nutrients and ca nopy closure within each 10 m2 vegetation-sampling block. The meso scale is the reach or site scale at which parameters such as river di scharge were recorded.
91 Macro variables consisted of data recorded at the catchment scale such as percentage forest cover in the watershed. Mega scale vari ables refer to very coarse scal e variables based on allocation of sample catchments into Ecoregions, geomorphol ogical units and high human impact vs. low human impact catchments (Table 3-1). Macro and mega scale data were de rived from GIS layers and pertinent literature, while micro and meso scale data were more based on field data. For more details on data collection see Chapter 2. Statistical Analyses Vegetation groups Hierarchical cluster analysis was used to de term ine riparian vegetation groups. Analyses were carried out using 10 m2 vegetation sample blocks, al ong 30 m transects at each site, amalgamated by distance from the river marg in (Figure 3-1) to provide three, 30 m2 blocks per site. Coarser scale analyses using combined vege tation data at each of the 36 sites were carried out to validate results of the bloc k data and to examine any other po ssible patterns at this scale. Cluster analyses were performed on tree abunda nce data (basal area) ground flora abundance data (percentage cover) as well as a combined tree and ground flora presence/absence data set. Non Metric Multi-Dimensional Sc aling (NMDS) was carried out to validate patterns derived from each cluster analysis. Clustering and NMDS were done using PRIMER (Plymouth Routines In Multivariate Ecological Research) Version 5.2.9. Plant data were first reduced for both cluster analysis and NMDS by eliminating the species that occurred at only one site. Tree basal area and gro und flora coverage data were 4th root transformed to reduce the impact of hi gh abundance species (C larke & Warwick 2001). Blocks and sites with no trees and ground flora were eliminated. Clustering and ordination were performed using the Bray-Curtis Similarity Inde x to emphasize abundant species within a data set and to ignore join t absences among sites (Clarke & Wa rwick 2001; McCune et al. 2002).
92 Clustering utilized the group av erage linkage clustering method, which uses the mean distance between group pairs (Clarke & Warwick 2001). Ten iterations were used for the NMDS procedure. The significance of differences in species composition between groups was tested using the analysis of similariti es (ANOSIM) routine in PRIMER. Th is is equivalent to a one-way ANOVA; however, the null hypothesi s is that there is no signif icant difference in species composition among groups. Indicator species analysis Species that typified a partic ular cluster group were determ ined using the SIMPER routine in PRIMER. This gives species percentage cont ribution to group similarity. A species with a high percentage contribution to the similarity in the group and low standard deviation suggests it was abundant and consistent at s ites within a group, and therefore, represents th e group (Clarke & Warwick 2004). SIMPER analysis was carried out on presence/absence data, tree abundance and ground flora abundance data. Tree basal area and ground flora cover data were 4th root transformed before SIMPER analysis to reduce the impact of abundant species. Environmental and anthropogenic determinants of riparian vegetation Data were recorded on 54 environm ental and anthropogenic variables, which were potential riparian vegetation determ inants (Table 3-1). Eight were categorical variables, six were ordinal and the other 40 were me tric data. Rankings for ordina l variables such as recreation intensity, fire, pollution and channe l modification, were based on a dditive effects at each site (Appendix G). For example, a site where bathing was the only re creational activit y was assigned a recreation ranking of 1, while a site with three recreational activities like bathing, cooking and shelter construction was assigned a ranking of 3 to indicate more in tensive use of the site. Sites were also ranked to indicate the level of edaphic modification (meas ure of human disturbance) of the riparian zone and the area 50 -100 m upland of the riparian zone. Sites with impervious,
93 irreversible land cover, for example, concrete buildings and paved roads were assigned the lowest ranking of 4 and sites with no modification 0. Further details of land use rankings and classifications are provided in Appendix H. Spearman rank correlations were performed (using SPSS version 15) on the 46 metric and ordinal variables to remove redundant variable s. Ten variables with correlations >0.7, p=0.001 (Appendix I) were removed. The remaining 36 metric and ordinal variables, along with eight categorical variables were subj ected to BIOENV and BVSTEP anal ysis in PRIMER to assess the relationship between vegetation clusters and environmental variables. These routines superimpose an environmental similarity matrix onto the vegetation similarity matrix, providing the best combinations of explanatory variable s, which produce the highest rank similarity ( ) between plant and environmental matrices (Clarke & Warwick 2001). BVSTEP uses a stepwise algorithm, moving forwards and backwards, adding and dropping variables to select the best matching variables to derive an optimal solution. BIOENV starts with one environmental variable moving up to a matrix of all variables. It is not recommended for analyses with more than 15 explanatory va riables (Clarke & Warw ick 2004); hence, BIOENV was used to find the best 1-6 variable solutions, while BVSTEP was used to assess a matrix of all 44 possible explanatory variables. Vegetation similarity matrices used in these two analyses were the identical Bray-Curtis Similari ty indices used in cluster analyses. Environmental/anthropogenic similarity ma trices were derived using a Log (x+1) Normalized Euclidean similarity measure. The six BIOENV selected variables were superimposed on presence/absence NMDS maps to graphically illustrate patterns between vegetation groups and variables. Additionally, individual Spearman rank correlations were performed between BIOENV variables and group indicator species abundance. Tree basal area
94 was log transformed before correlation analyses to reduce the effect of high basal areas species like Bambusa vulgaris. Transformations were not necessary for ground flora data given the relatively small percentage cover range compared to tree basal area. The significance of rank correlations between plant similarity matrices an d environmental/anthropogenic data was tested using the RELATE routine in PRIMER. This is a permutation procedur e (n=999 permutations) testing the null hypothesis that there is no rela tionship between environmental and vegetation matrices. For this test, is calculated using all the environmental variables and if it is greater than the value found in 95% of the permutatio ns, then the null hypothesis can be rejected. BIOENV analyses were conducted using 30 m2 combined blocks (micro scale) as the basic analytical unit for both plant and environmental data. Average valu es for the three blocks were used for cumulative elevation and slope. For bank slope and elevation data constants were added to remove negative values before statistical anal ysis. Missing soil data were replaced using either the series means for the transect or data for th e site soil type as de scribed in Brown & Bally (1968). This was necessary for 1.95% of the soil data, which were missing due to human error in the field or laboratory. Results Nine m ajor vegetation clusters were found. These were seen in the presence/absence data and were also evident in the ground flora and/or tree data. Groups were as follows: Justicia secunda-Eschweilera subglandulosa, Mora excelsa-B actris major, Bambusa vulgaris, Flemingia strobilifera, Saccharum officinarum, Ju sticia secunda, Axonopus compressus, Sorghum sp. and Acroceras zizanioides Groups were named using dominant sp ecies (highest % contribution) in each group as seen in the presence/absence data. Groups and indicator species for all three data sets are listed in Tables 3-2, 3-3 and 3-4 and demarcated on de ndrograms in Figures 3-2, 3-3 and 3-4.
95 Only groups at the 10% simila rity level from the amalgamated block data have been reported, as in all cases the coarser scale site le vel clusters echoed block data patterns, validating block level clusters, as was expected. ANOSIM s howed that groups at th e 10% similarity level were significant for all three data sets (p resence/absence-global R 0.623, p=0.001; ground flora global R 0.679, p=0.001; tree data global R 0.779, p=0.001). NMDS analysis validated groups found in cluster analysis. Figure 3-5 shows th e presence/absence NMDS map (stress value 0.2) and the nine major vegetation groups superimposed on the ordination map. BVSTEP results (Table 3-5) s howed a combination of six variables that best explained the presence/absence vegetation data set ( =0.445). Variables included canopy closure, fire, geomorphology, channel modification, upland eda phic modification and form factor. The BVSTEP best solution for the groun d flora was eight variables ( =0.429) including all aforementioned variables except upland edaphic m odification, which was replaced by riparian zone edaphic modification land ownership. The BVSTEP results for the trees showed a best combination of 14 variables listed in Table 3-5, but with a lower of 0.321. BIOENV results showed canopy closure was the mo st important single variable explaining vegetation community patterns in the presence/absence and ground flora data sets. However, with tree data, the strongest sing le explanatory variable was up land edaphic modification (Table 3-5). Best six variable BIOENV solutions are also shown in Table 3-5. Six variables was the cut off point as this was the number of variables in the BVSTEP presence/absence solution and also a manageable number of variables for comparis on. The best six variable BIOENV solution for both the presence/absence and ground flora data included geomorphology, channel modification, fire, form factor and canopy closure. However, the presence/absence data also had upland edaphic modification, while in the ground flora upland edaphic modification was replaced by
96 either riparian zone edaphic modification or land ownership. There were two alternatives for the ground flora as riparian zone edaphic modifica tion and land ownership could be substituted for each other with the same resulting value of 0.420. The best six va riable solution for the tree data included distance from paved roads, form factor, pollution, upla nd edaphic modification, geomorphology and canopy closure. RELATE analyses indicated significant relationships (p<0.05) between all vegetation and environm ental/anthropogenic similarity matrices. Bubble plot graphs (Figure 3-5) and indicator species correlations (Table 3-6) showed that the Saccharum officinarum (Sugarcane) group was positively correlated with fire, and negatively correlated with canopy closure. This is expected as sugarcane is gown in large fields devoid of tree canopy and fire is used in the sugarcane harv esting process. The Axonopus compressus (Lawn grass) group was comprise d of blocks either in citrus orchards or in a soccer field where grass was used as ground cover. In the tree data set, the Axonopus compressus group was typified by Citrus sp. This group was found along modi fied river channels on private land (Table 3-6 and Figure 3-5). Both Saccharum officinarum and Axonopus compressus groups can be regarded as agricultural groups. The Sorghum sp. group was associated with modified channels, low canopy closure, high riparian zone edaphic modification and low catch ment form factor (Fi gure 3-5 & Table 3-6). Sorghum sp. is a weedy grass, and the Sorghum sp. group as a whole had a number of weeds like Pueraria phaseoloides and Euphorbia hyssopifolia L. Another grass, Acroceras zizanioides typified another group. It is a native grass, found in moist and swampy areas (Adams & BakshComeau Unpublished). This gr oup also had the native grass Paspalum fasciculatum Willd. ex Flgg, which has been previously found in ripari an areas. This group is associated with low canopy closure (Figure 3-5).
97 An introduced weed, F. strobilifera, typified another group. Th is group was most strongly associated with fire (Table 3-6 & Figure 3-5). B. vulgaris, an introduced grass (Adams & BakshComeau Unpublished), characterized the larges t tree group consisting of 29 blocks across the island. This group was also evident in the presence/absence data set. B. vulgaris was found at sites with upland edaphic modification (Table 3-7 and Figure 3-5). The Mora excelsa-Bactris major group was found in unpolluted sites with low edaphic modification, both within and upland of the ri parian zone. The group was found in the South Geomorphological Unit, in short watersheds (hig h form factor) on public land (Tables 3-6, 3-7 and Figure 3-5). Mora excelsa is a forest tree species, and Bactris major is a palm found along rivers, in swamps and forest understories (Adams & Baksh-Co meau Unpublished). The Justicia secunda-Esch weilera subglandulosa group was restricted to sample blocks at one site in the North Geomorphological Unit (Fi gure 3-5). This group was associated with low levels of pollution, low edaphic modification both within and upland of the riparian zone, low incidence of fire but high canopy cove r. (Tables 3-6, 3-7 and Figure 3-5). Eschweilera subglandulosa is a common forest tree species. Terminalia amazonia (J.F. Gmel.) Exell was also found in this group. While the tree E. subglandulosa typified this group in the presence/absence data, the high basal area of T. amazonia resulted in the dominance of this species in the equivalent tree data group. The Mora excelsa-Bactris major and Justicia secunda-Eschweilera subglandulosa group could be regarded as representativ e of south and north riparian forest, respectively. The largest vegetation group was the Justicia secunda group, which in the presence/absence data was comprised of 45 blocks distributed across Trinidad. J. secunda is a ground flora species, associated with mois t, shady areas (Adams & Baksh-Comeau
98 Unpublished). C. peltata and Spondias mombin represented the Justicia secunda group in the tree data, as 17 of the 23 blocks in this tree group were also in the Justicia secunda group in the presence/absence data set. C.peltata and S. mombin are common disturbed/secondary vegetation species (Adams & Baksh-Comeau Unpublished) This group was associated with a low incidence of fire, low riparian zone edaphic modification but high canopy closure (Table 3-6, Figure 3-5) Apart from these major groups, there were minor groups found in only one data set or with only one or two blocks in the group. These are described in Tabl es 3-2, 3-3, 3-4. They included Group 1 in the presence/absence data set, which consisted of two sites along the Poole River with Zygia latifolia (L.) Fawc. & Rendle. Gr oup 9 in the presence/absenc e data set consisted of one 10 m combined block at the Caparo Middle Reach site (CAPM). It is the only block and site with Crudia glaberrima commonly called Water Locust. Group 4 of the ground flora data was typified by Inga ingoides common in moist, disturbed areas (Adams & Baksh-Comeau Unpublished). Group 7 of the ground flora data was typified by Pueraria phaseoloides, a weedy species. There were six minor groups in the tree data set including Group 1 characterized by Musa sp. (Banana) and Group 10 dominated by the fruit tree Syzygium malaccense (Pomerac). There was also a Tectona grandis (Teak) group consisting of all three combined blocks at the Penal Upper (PENU) site in south Trinidad, and a Cordia collococca dominated group also in the Southern Plain. In the Northern Range, there wa s a group of two blocks, at separate sites with Ochroma pyramidale (Cav. ex Lam.) Urb. in common. Th e last minor tree group was typified by Lonchocarpus sericeus found at sites in both the North and South Geomorphological Units.
99 Discussion Vegetation Groups Nine m ajor vegetation groups were identified and named according to typifying species, distribution and major determinants. These are Justicia secunda-Eschweilera subglandulosa (North Forest), Mora excelsa-Bactris major (South Forest), Saccharum officinarum (Agricultural), Axonopus compressus (Agricultural), Justicia secunda (Secondary Vegetation), Flemingia strobilifera (Fire Influenced), Sorghum sp. (Weedy Species), Acroceras zizanioides (Native Grasses) and Bambusa vulgaris (Bamboo) groups. The Justicia secunda (Secondary Vegetation) sample blocks coalesced on the basis of ground flora species such as Justicia secunda and trees like Cecropia peltata and Spondias mombin. J. secunda was also a typifying species of the Justicia-Eschweilera (North Forest) group. However, cluster analysis separated these two groups due to the presence of forest trees in the latter group, instead of agricu ltural species in the former. Agricultural spec ies were in the Justicia secunda group, as sites in this group were loca ted in abandoned agricultural estates. From a practical perspective, the north forest gr oup can serve as an example of native riparian vegetation typical of Beards ( 1946) Lower Montane Rain Forest, which he described for the Northern Range in Trinidad. In the NMDS ma ps (Figure 3-5) the Caura Middle Reach (CAUM) blocks were located in the vi cinity of the north forest group indicating similar species composition. However, cluster analysis pla ced these blocks into the bamboo dominated vegetation group pointing to the influence of B. vulgaris on vegetation groupings and overall structure and composition of riparian vegetation in Trinidad. The species composition of the south forest riparian group was expected, as sample blocks fell within the geographic range of Beards (1946) Mora faciation of Evergreen Seasonal fo rest. This, Beard (1946) noted as consisting of almost monotypic stands of Mora excelsa
100 The weedy species group had a prevalence of ex otic species including the indicator species Sorghum sp. Native riparian plants are often out-competed by exotics, which are suited to high disturbance conditions in ripari an areas. Exotics may also be promoted by hydrological alteration (National Research Counc il 2002). This was seen in Trinidad where Sorghum sp. was positively correlated with channel modification. Exotic species are often deliberately introdu ced into riparian areas, for example, for riverbank stabilization, or indirectly introduced, for example, through dispersal along roads. The exotic species B. vulgaris was planted along rivers in Trinid ad for bank stabilization (Forestry Division pers comm.). El sewhere in the Caribbean, O'Connor et al. (2000) li nked the dominance of monotypic bamboo stands along rivers in Puerto Rico to the plants ability to reproduce vegetatively. In particular, they highlighted the ability of broken culms to reestablish downstream after transportation al ong the river. It is likely that the same processes have accounted for the dominance of bamboo in riparian areas in this study. Environmental and Anthropogenic Det erminants of Riparian Vegetation For this study, block data at each site were pooled for cluster anal ysis based on distance from river, i.e, 10 m blocks, 20 m blocks and 30 m blocks. As seen in Tables 3-2, 3-3 and 3-4, the amalgamated blocks tended to cluster more on the basis of sites than distance from river. Distance from river has been used as a proxy for flooding regime in riparian studies (Turner et al. 2004), and flooding is acknowledged as one of the main riparian vegetatio n influencing factors (Tabacchi et al. 1998; Bendix & Hupp 2000). In Tr inidad; however, neither flooding nor other hydrological factors were strong predictors of riparian vegetation groups. However, distance from river was one of the variables in the eigh t variable BVSTEP soluti on for the ground flora, indicating some influence on the di stribution of ground flora plants.
101 In Trinidad, the best predicto rs of riparian vegetation groups appear to be canopy closure, degree of upland and riparian zone edaphic modification, geomorphology, fire, channel modification, distance from paved roads, land ownership, pollution a nd form factor. Canopy closure, one of the strongest pr edictors in this study, is a ke y determinant of riparian ground flora, as it affects the amount of light avai lable to ground flora species (Naiman & Decamps 1997). Form factor is the ratio of catchment area to the square of catchment length. A higher form factor implies a shorter catchment. Smaller, sh orter catchments tend to have more surface runoff resulting in faster sediment a nd nutrient delivery to the ripari an zone (Gregory & Walling 1973). Thus, the positive correlation of Mora excelsa and Bactris major with form factor suggests that these indicator species and associated groups are to lerant of, or are effect ively able to exploit rapid buildups of sediment and nutri ents in the riparian zone. The Mora excelsa-Bactris major forest group was in south Trinid ad and the other forest group Justicia secunda-Eschweilera subgladulosa in north Trinidad. Hence, the role of geomorphology as a predictor of riparian vegetation is noted. However, this may not be sp ecific to riparian vege tation as south sample blocks fell within the geogra phic range of Beards (1946) Mora faciation of Evergreen Seasonal forest, while Justicia secunda-Eschweilera subglandulosa group was in the range of Beards (1946) Lower Montane Forest. Edaphic modification included beds, furrows, di rt roads, soil compaction along trails, and paved areas or concrete buildi ngs. These changes are reflective of human intervention, for example, agriculture or urbanization. Within-z one modification influenc ed ground flora patterns while upland modification influe nced tree groups. Soil compaction or creation of impervious surfaces, whether within or upland of riparian areas, can alter surface runoff and nutrient delivery
102 to riparian vegetation affecting growth and di stribution of the plants. Researchers including Petersen (1992) have also found that land use beyond 100 m was a us eful determinant of riparian vegetation patterns, particularly for small rivers. Forest groups were associated with low edaphic modification, while agricultural groups were associated with highe r levels of edaphic modification as to be expected. Other relevant anthropogenic variables included fire, which wa s positively associated with the Flemingia strobilifera and Saccharum officinarum groups. As mentioned before, fire is used in harvesting sugarcane Flemingia strobilifera group species may be fire tolerant. Supporting evidence is seen in Ross (1961) who noted the association of Bactris spp. and Spondias mombin ( Flemingia strobilifera group members) with burnt teak fields. Agricultural groups were associated with ch annel modification in riparian areas. Although agricultural group species may be flood tolerant, it is more likel y that dredging in agricultural areas reduced the likelihood of flooding, thus, allowing agricultural species to survive. Agricultural groups were more prevalent on private land, while forest groups were more likely to be found on public land. In particular the Mora excelsa-Bactris major groups were located in forest reserves in south Trinidad. Of the initial 54 variables, 10 were elimin ated from analyses based on significant correlations of > 0.7 (p=0.001). Eliminated vari ables included 60 cm soil parameters, which were correlated with their c ounterparts at the 30 cm soil dept h. While relationships with environmental variables were significant overa ll, weak correlations between vegetation and environmental/anthropogenic matrices suggested that the explanator y variables did not sufficiently explain the vegetation patterns. We ak correlations were also evident between individual indicator species a nd environmental/anthropogenic variab les. However, Naiman et al.
103 (2005) suggested that it is sometimes difficult to link vegetation and environmental variables in riparian zones due to patchy abiotic conditions. Variable Scales Riparian vegetation groups in Trinidad were inf luenced by variables at different scales. At the micro scale, canopy closure wa s significant, while at the meso scale, edaphic modification (riparian and upland), fire, pollution, land ownership and channel modification were important. Form factor was a significant ca tchment (macro) level variable, and geomorphological unit was a vegetation group determinant at the mega (island) scale. This st udy, therefore, supports others, for example, Baker (1989) and Turner (2004) that point to th e importance of variables at different scales in expl aining riparian vegetation structure and function. Baker (1989) found that coarse scale watershed characteristics explained more variance in riparian vegetation than micro scale variables in Western Colorado, USA. Similarly, Turner (2004) found that coarse scale physiographic data were more important than fine scale soil parameters in explaining riparian vegetation patterns in Wisconsin, USA. However, Streng et al. (1989) and Robertson & Augspurger (1999) and found that fine scal e variables like soil texture and light were more important explanatory variables in Louisiana, USA. It thus appears difficult to generalize about the relative importance of differe nt scales of variables. In Trinidad, out of a 4-level hierarchy of variables, the highest number of significant variables (four out of six for the presence/absence data set) was at the meso scale. However, the strongest correlation of those six variables was canopy closure at the micro scale. In addition to different scales of variables a ffecting riparian vegetation, variables are often linked (Baker 1989; Naiman et al. 2005). Moreover patterns and processes in ecosystems are believed to operate simultaneously in a multi-scal e hierarchy (Allen & Starr 1982; Turner et al. 1989). For example, larger, longer catchments of ten have wider channels and higher discharge
104 (Gregory & Walling 1973; Baker 1989) This in turn influences flooding regime and riparian vegetation. Allan et al. (1997) not ed that catchment relief and geology influence sediment and nutrient delivery to rivers and ri parian systems, thus linking co arse scale catchment factors to micro scale soil factors. Both scales of variable s interacted and simultane ously impacted riparian vegetation. In Trinidad, while multi-scale variables impacted riparian vegetation links between the different scales of significant variables were not easy to discern. For example, even though high form factor (short watersheds) is normally a ssociated with faster sediment and nutrient delivery to riparian zones, ther e was no significant co rrelation between this macro scale factor and micro scale factors at sites in Trinidad. With the exception of canopy closure, micro scale soil factors were overall not impor tant determinants of riparian vegetation in Trinidad. Given the importance of anthropogenic variables like fire and channel modification in shaping riparian vegetation in Trinidad, it is likely that multi-sc aled linked environmental variables were not that relevant. Riparian Species in Trinidad Possible riparian species from Adams & Baksh-Comeau (Unpublished) have been identified in Table 2-12 (Chapter 2). This chap ter provides additional suggestions for Trinidadian riparian species using the forest vegetation group indicator species, which contributed more than 50% of the group similarity (Table 3-8). These vegetation groups represented the most natural state vegetation in the study. Some forest group species, for example, Bactris major, do in fact overlap with possible riparian species as listed by Adams & Baksh-Comeau (Unpublished). Indicator species for agriculture, fire tolerant and weedy specie s groups were not included in Table 3-8, as species were either exotics, plan ted for agriculture or their presence may be the result of non-riparian factors. Fo r this reason, the exotic s from Table 2-12 (Cha pter 2) were also removed from Table 3-8 to provide a final list of 57 native riparian species for Trinidad.
105 Non agricultural, native indicator species f ound in secondary vegetation groups, were also included as possible riparian spec ies in Table 3-8, as it was felt that conditions at sites with secondary vegetation approximated forested conditions. Thus, species such as Costus scaber and Heliconia bihai/spatho-circinada were included as riparian species. E. subglandulosa was also included in Table 3-8. While this is a species typical of the widespread Evergreen Seasonal Forest Association (Beard 1946), and therefore, not limited to riparian zones, its presence indicates tolerance of ripari an conditions. The secondary ve getation generalist and pioneer species Cecropia peltata was also included as a riparian sp ecies for this same reason. Further research is needed to differentiate faculta tive and obligate riparian species, including experimental work to verify the conditions under which such species can survive. Conclusion Hum an intervention was the major influence on riparian vegetation inclusive of riparian zone and upland edaphic modification, channel modification, pollution, land ownership and fire. These variables exerted their effect at the meso or reach level. While this study showcased the high level of human interaction a nd subsequent degradation of riparian zones in Trinidad, it can also form the basis for riparian restoration a nd conservation using the information generated on riparian groups, indicator speci es and their determinants. The forest groups are representative of natu ral state conditions. These should be conserved along with other areas in Trinidad with simila r species composition. Forest groups can also be used as reference vegetation types, for choosing the best species and species combinations for restoration of disturbed riparian areas. Potential restoration plants can also be drawn from native riparian species determined in this study. Reference conditions should be specific to the geomorphological region, as differe nces between north and south fo rested riparian sites were found in this study. Given the low number of site s in the forest groups, sites with secondary
106 vegetation may be the next best alternative for riparian conservation reference sites, especially advanced secondary growth sites with remnant or re-established riparian plants. Degraded sites can be restored by, inter alia re-establishing the original hydrol ogical regime and natural species composition of the area. Physically modified or fire prone sites may not be suitable for conservation or restoration given persistent human interaction. Sites with agricultural vegetation are a better restorati on alternative if hydrology can be restored.
107 Table 3-1. Scales of environmental and anth ropogenic variables m easured in the study Scale Variable type Variable Mega Categorical Ecoregion: Dry vs. Wet Mega Categorical Gemorophological Unit: Northern Range vs. Central Plain vs. Southern Plain. Mega Categorical Level of human im pact: High impact vs. low impact Macro Metric Catchment area Macro Metric Catchment length Macro Metric Catchment relief (relief ratio) Macro Metric Catchment shape (form factor) Macro Metric Maximum basin relief Macro Metric Percentage forest cover in watershed (1994 & 2001) Meso Categorical Evidence of braiding Meso Categorical Evidence of meandering Meso Categorical Land ownership: private vs. public Meso Categorical Presence/absence of animal activities Meso Categorical Soil type Meso Metric Distance from sample point to nearest paved road Meso Metric Elevation above sea level Meso Metric Mean bankfull depth Meso Metric Mean bankfull width Meso Metric Mean channel width Meso Metric Mean river discharge Meso Metric Mean riverbank slope Meso Metric Number of land cover types per reach Meso Metric Riverbank length Meso Ordinal Channel modification, for example, channelization or dredging Meso Ordinal Fire Meso Ordinal Level of human modification of the site Meso Ordinal Level of human modi fication 50-100 m upland of site Meso Ordinal Pollution Meso Ordinal Recreation intensity Micro Metric Canopy closure Micro Metric Distance of transect block from waters edge (length along transect) Micro Metric Elevation above water margin Micro Metric Slope Micro Metric Soil calcium (0-30 cm & 30-60 cm) Micro Metric Soil organic carbon content (0-30 cm & 30-60 cm) Micro Metric Soil particle size (% sand,% silt,% gravel,% clay) 0-30 cm level only Micro Metric Soil pH (0-30 cm & 30-60 cm) Micro Metric Soil plant available phosphates (0-30 cm & 30-60 cm) Micro Metric Soil magnesium (0-30 cm & 30-60 cm) Micro Metric Soil electroconductivity (0-30 cm & 30-60 cm) Micro Metric Soil potassium (0-30 cm & 30-60 cm) Micro Metric Soil total nitrogen (0-30 cm & 30-60 cm)
108Table 3-2. Indicator species for vege tation group clusters of presence/absen ce data for 108 amalgamated blocks Group Blocks Group name Indicator species contributing to >50% of cumulative similarity within group % contribution to group similarity 1 POOL1, POOU3 Zygia latifolia Zygia latifolia (L.) Fawc. & Rendle 50.00 2 MORL1 MORL2 MORL3 MORM2 MORM3 MORU1 MORU2 MORU3 PENL1 PENL2 PENL3 PENM1 PENM2 PENM3 Mora excelsa Bactris major Mora excelsa Benth. Bactris major Jacq. Costus scaber Ruiz & Pav. Swartzia pinnata (Vahl) Willd. Sabal mauritiiformis (H. Karst.) Griseb. & H. Wendl. 17.39 17.20 8.00 6.40 4.74 3 CAUL2 CAUM1 CAUM2 CAUM3 COUL1 COUL2 COUL3 CUMU1 Bambusa vulgaris Bambusa vulgaris Schrad. ex J.C. Wendl. Andira inermis (W. Wright) Kunth ex DC. 45.23 17.61 4 CAPM2 CAPM3 CAUL1 COUM1 PENU1 PENU2 PENU3 Flemingia strobilifera Flemingia strobilifera (L.) R. Br. Bactris major Jacq. Spondias mombin L. 28.29 17.43 15.36 5 NORU1 NORU2 NORU3 Justicia secundaEschweilera subglandulosa Justicia secunda Vahl Eschweilera subglandulosa (Steud. ex O. Berg) Miers Terminalia amazonia (J.F. Gmel.) Exell 23.27 23.27 8.08 Data clustered using Bray Curtis Similarity Index with group average linkage on a reduced data set of plants found in more than one transect. Groups described at the 10% similarity level.
109Table 3-2. Continued Group Blocks Group name Indicator species contributing to >50% of cumulative similarity within group % contribution to group similarity 6 ARIM1, ARIM2 ARIM3 ARIU1 ARIU2 ARIU3 AROM1 AROM2 AROM3 AROU1 AROU2 AROU3 CAUU1 CAUU2 CAUU3 COUM2 COUM3 COUU1 COUU2 COUU3 CUML1 CUML2 CUML3 CUMU2 CUMU3 LEBL1 LEBL2 LEBL3 LEBM2 LEBM3 LEBU1 LEBU2 LEBU3 NORL1 NORL2 NORL3 NORM1 NORM2 NORM3 POOL2 POOL3 POOM2 POOM3 POOU2 POOU3 Justicia secunda Justicia secunda Vahl Costus scaber Ruiz & Pav. Bambusa vulgaris Schrad. ex J.C. Wendl. Heliconia bihai or spatho-circinada Dieffenbachia seguine (Jacq.) Schott Pueraria phaseoloides (Roxb.) Benth. Blechum pyramidatum (Lam.) Urb. 13.47 11.23 6.96 6.47 5.91 4.80 4.65 7 CUMM1 CUMM2 CUMM3 CAUL3 Axonopus compressus Axonopus compressus (Sw.) P. Beauv. Poaceae 31.34 26.39 8 ARIL1 ARIL2 ARIL3 AROL1 AROL2 AROL3 CAPL1 CAPL2 CAPL3 CAPU2 Sorghum sp. Sorghum sp. Pueraria phaseoloides (Roxb.) Benth. Euphorbia hyssopifolia L. 28.56 12.71 11.99 9 CAPM1 Only one block in the group, with Crudia glaberrima (Steud.) J.F. Macbr. exclusive to this site 10 CAPU3, SOUU3, SOUM3, SOUU2 Saccharum officinarum Saccharum officinarum L. 100.00 11 SOUL1 SOUL2 SOUL3 SOUM1 SOUM2 SOUU1 MORM1 CAPU1 POOM1 Acroceras zizanioides Acroceras zizanioides (Kunth) Dandy Paspalum fasciculatum Willd. ex Flgg 34.66 17.96 Data clustered using Bray Curtis Similarity Index with group average linkage on a reduced data set of plants found in more than one transect. Groups described at the 10% similarity level.
110Table 3-3. Indicator species fo r group clusters of ground flora for 108 amalgamated blocks. Group Blocks Group name Indicator species contributing to >50% of cumulative similarity within group % contribution to group similarity 1 CAPU2 CAPU3 SOUM2 SOUM3 SOUU2 SOUU3 Saccharum officinarum Saccharum officinarum L. 98.02 2 CAUL3 CUMM2 CUMM3 Axonopus compressus Axonopus compressus (Sw.) P. Beauv. 73.86 3 ARIL1 AROL1 AROL2 AROL3 CAPL1 CAPL2 CAPL3 CAPU1 CUMM1 Sorghum sp. Sorghum sp. Poaceae 47.27 17.53 4 CAUM1 CAUM2 CAUM3 CUML1 LEBM1 MORM3 MORU2 MORU3 NORL1 NORL2 NORL3 POOU1 Inga ingoides Inga ingoides (Rich.) Willd. Oplismenus hirtellus (L.) P. Beauv. Adiantum sp. 26.14 14.73 14.23 5 MORU1 Less than two samples in the group 6 ARIM1 ARIU1 ARIU2 ARIU3 AROU1 AROU2 AROU3 CAUU1 CAUU2 CAUU3 COUM2 COUM3 COUU1 COUU2 COUU3 CUML2 CUML3 CUMU1 CUMU2 CUMU3 LEBL2 LEBL3 LEBM2 LEBM3 LEBU2 LEBU3 NORM3 NORU1 NORU2 NORU3 POOL1 POOL2 POOL3 POOM2 POOM3 POOU2 POOU3 Justicia secunda Justicia secunda Vahl Costus scaber Ruiz & Pav. Heliconia bihai or spatho-circinada Coffea sp. 30.68 9.62 9.18 9.00 7 ARIM3 AROM1 AROM2 AROM3 LEBU1 NORM1 NORM2 Pureria phaseoloides Pueraria phaseoloides (Roxb.) Benth. Scleria melaleuca Rchb. ex Schltdl. & Cham. Hippobroma longiflora (L.) G. Costus scaber Ruiz & Pav. Blechum pyramidatum (Lam.) Urb. 18.29 12.00 10.21 8.94 7.93 8 MORL1 MORL2 MORL3 PENL1 PENL2 PENL3 PENM1 PENM2 PENM3 PENU2 PENU3 Bactris major Bactris major Jacq. 73.03 9 ARIM2 CAPM2 CAPM3 CAUL1 COUL1 COUL2 COUL3 COUM1 PENU1 Flemingia strobilifera Flemingia strobilifera (L.) R. Br. 59.02 Data clustered using Bray Curtis Similarity Index with group average linkage on a reduced data set of plants found in more than one transect. Ground flora percentage cover data 4th root transformed prior to analysis. Groups described at the 10% similarity level.
111Table 3-4. Indicator species for group clusters of trees for 84 amalgamated blocks. Group Blocks Group name Indicator species contributing to >50% of cumulative similarity within group % contribution to group similarity 1 CUMM1 CUMM2 CUMM3 Citrus sp Citrus sp. 100.00 2 CAPU1 CAUL1 CAUL2 CAUM1 CAUM2 CAUU1 CAUU2 CAUU3 COUL1 COUL2 COUL3 COUM1 COUM2 COUU1 COUU2 COUU3 CUML1 CUML2 CUMU1 CUMU3 LEBL1 LEBL2 LEBM1 LEBM3 NORL1 NORM1 NORM3 POOM1 SOUL1 Bamboo vulgaris Bambusa vulgaris Schrad. ex J.C. Wendl. 98.99 3 PENL2 SOUM1 Cordia collococca L. 100.00 4 NORU1 NORU2 Terminalia amazonia Terminalia amazonia (J.F. Gmel.) Exell Hieronyma laxiflora (Tul.) Mll. Arg. 41.01 31.36 5 PENM1 MORL1 MORL2 MORL3 MORM2 MORU1 MORU2 MORU3 NORU3 Mora excelsa Mora excelsa Benth. 51.04 6 ARIM3 NORM2 Ochroma pyramidale Ochroma pyramidale (Cav. ex Lam.) Urb. 100.00 7 POOM3 POOU2 POOU3 AROM1 Syzgium malaccense Syzygium malaccense (L.) Merr. & L.M. Perry 64.08 8 POOL3 Only one site in group 9 PENU1 PENU2 PENU3 Tectona grandis L. f. 100.00 10 COUM3 POOM2 Musa sp. 100.00 11 ARIU1 AROU2 POOL1 POOU1 Lonchocarpus sericeus (Poir.) Kunth ex DC 65.66 12 NORL3 AROM2 ARIM1 ARIM2 ARIU2 ARIU3 AROM3 AROU1 AROU3 CAPM2 CUML3 LEBL3 LEBM2 LEBU1 LEBU3 MORM3 NORL2 PENL1 PENL3 PENM2 PENM3 SOUL2 POOL2 Cecropia peltata Cecropia peltata L. Spondias mombin L. 39.93 30.96 Data clustered using Bray Curtis Similarity Index with group average linkage on a reduced data set of plants found in more than one transect. Groups described at the 10% similarity level.
112Table 3-5. BIOENV and BVSTEP results Data set Analysis No. of variables Variables Presence/ absence BIOENV 1 44 0.391 BIOENV 6 9,31,33,35,38,44 0.445 BVSTEP (optimal variable solution out 44 possible explanatory variables ) 6 9,31,33,35,38,44 0.445 Ground flora BIOENV 1 44 0.324 BIOENV 6 9,31,33,34/43,38,44 0.420 BVSTEP (optimal variable solution out of 44 possible explanatory variables ) 8 4,9,31,33,34,38,43,44 0.429 Trees BIOENV 1 35 0.267 BIOENV 6 5,9,32,35,38,44 0.313 BVSTEP (optimal variable solution out of 44 possible explanatory variables ) 14 5,6,9,13,23,25,28,32,35, 38,39,42-44 0.321 1 clay 2 silt 3 gravel 4 distance from river (m) 5 distance from paved road (m) 6 elevation above sea level (m) 7 cat chment length (km) 8 maximum basin relief 9 form factor (area/length 2) 10 percentage forest cover (1994) 11 pH (30 cm) 12 N (30 cm) (g kg-1) 13 P(30 cm) (mg kg-1) 14 K(30 cm) (c mol kg-1) 15 Ca (30 cm) (c mol kg-1) 16 Mg (30 cm) (c mol kg-1) 17 EC (30 cm) (mS cm-1) 18 OC (30 cm) (g kg-1) 19 N (60 cm) (g kg-1) 20 OC (60 cm) (g kg-1) 21 discharge (m3) 22 channel width (m) 23 bankfull width (m) 24 bank length (m) 25 bank slope+60 26 average slope+50 27 average elevation (m) 28 number of land use types 29 maintenance activities 30 recreation intensit y 31 channel modification 32 pollution 33 fire 34 edaphic modification in riparian zone 35 edaphic modification upland of rip arian zone (50-100 m) 36 catchment impact level 37 Ecoregion 38 geomorphology 39 animal presence/absence 40 braiding 41 meande ring 42 soil type 43 land ownership 44 average canopy closure
113 Table 3-6. Correlations between ground flora indicator species abundance and metric a nd ordinal variables from the 1-6 BIOENV variable solutions Species Form factor (area/length2) Channel modification Fire Riparian edaphic modification Average canopy closure Axonopus compressus (Sw.) P. Beauv. -0.074 0.265(**) -0.028 0.237(*) -0.208(*) B actris majo r Jacq. 0.430(**) -0.236(*) 0.153 -0.08 -0.053 F lemingia strobilifera (L.) R. Br. 0.047 -0.052 0.313(**) 0.033 0.033 I nga ingoides (Rich.) Willd. -0.103 -0.007 -0.104 -0.072 0.255(**) J usticia secunda Vahl -0.105 -0.159 -0.299(**) -0.206(*) 0.268(**) P aspalum fasciculatum Willd. ex Flgg -0.001 0.157 0.269(**) -0.007 -0.311(**) P ueraria phaseoloides (Roxb.) Benth. -0.159 0.07 -0.072 0.152 -0.216(*) Saccharum officinarum L. 0.064 0.221(*) 0.379(**) 0.247(*) -0.374(**) A croceras zizanioides (Kunth) Dandy 0.058 0.61 0.269 (**) -0.054 -0.0223(*) Sorghum sp. -0.293(**) 0.361(**) 0.099 0.326(**) -0.382(**) significant at p=0.01 ** significant at p=0.001 Table 3-7. Correlations between tree indicator species abundance and metric and ordinal variab les from the 1-6 BIOENV variable solutions Species Distance from paved road (m) Form factor (area/l2) Pollution Upland edaphic modification Average canopy closure Bambusa vulgaris Schrad. ex J.C. Wendl. -0.099 -0.079 0.236(*) 0.310(**) 0.009 Cecropia peltata L. -0.184 -0.025 0.131 -0.076 0.139 Citrus sp. 0.121 -0.096 -0.161 0.143 -0.218(*) Mora excelsa Benth. 0.057 0.362(**) -0.305(**) -0.370(**) 0.136 Terminalia amazonia (J.F. Gmel.) Exell -0.177 -0.036 -0.093 -0.233(*) 0.138 E schweilera subglandulosa (Steud. ex O. Berg) Miers -0.013 0.071 -0.227(*) 0.350(**) 0.123 significant at p=0.01 ** significant at p=0.001
114Table 3-8. List of Ripari an species for Trinidad. Scientific name Common Name in Trinidad A croceras zizanioides (Kunth) Dandy A diantum sp. A ndira inermis (W. Wright) Kunth ex DC. B actris majo r Jacq. Gru-Gru Calathea lutea Schult. Sohari Leaf Carapa guianensis Aubl. Crappo Casearia sylvestris Sw. Cecropia peltata L. Cnemidaria ?spectabilis Tree fern Combretum fruticosum (Loefl.) Stuntz Cordia collococca L. Costus scaber Ruiz & Pav. Crudia glaberrima (Steud.) J.F. Macbr Water Locust Cyclanthus bipartitus Poit Cyperus luzulae (L.) Rottb. ex Retz. Cyperus surinamensis Rottb. E schweilera subglandulosa (Steud. ex O. Berg) Miers F aramea occidentalis (L.) A. Rich F icus yaponensis Desv Gynerium sagittatum (Aubl.) P. Beauv. H eliconia bihai (L.) L. Baliser H eliconia bihai or spatho-circinada H eliconia hirsuta L. f. H ieronyma laxiflora (Tul.) Mll. Arg. H ymenachne amplexicaulis (Rudge) Nees H ypoderris brownii J.Sm. I sertia parviflora Vahl J usticia comata (L.) Lam. L asiacis ligulata Hitchc. & Chase
115Table 3-8. Continued. Scientific name Common Name in Trinidad L eptochloa ?longa L omariopsis japurensis (Mart.) J.Sm. L onchocarpus heptaphyllus (Poir.) DC. L onchocarpus sericeus (Poir.) Kunth ex DC. Manilkara bidentata (A. DC.) A. Chev. Balata Mimosa pigra L. Mouriri rhizophorifolia (DC.) Triana Monkey bone P achystachys coccinea (Aubl.) Nees Black stick P alicourea crocea (Sw.) Roem. & Schult. P anicum ?frondescens P aspalum fasciculatum Willd. ex Flgg Bull grass P harus latifolius L. P henax sonneratii (Poir.) Wedd. P iper ?aequale P iper ?hispidum P iresia sympodica (Dll) Swallen P sychotria capitata Ruiz & Pav. P terocarpus officinalis Jacq. Bloodwood P terolepis glomerata (Rottb.) Miq. Quiina cruegeriana Griseb. R enealmia alpinia (Rottb.) Maas Sapindus saponaria L. Soapseed Spathiphyllum cannifolium Schott. Maraval lilly Thelypteris serrata (Cav.) Alston Tripogandra serrulata (Vahl) Handlos Virola surinamensis (Rol. ex Rottb.) Warb. Vismia cayennensis (Jacq.) Pers.
116 Figure 3-1. Combined vegetation sample bloc ks, used in hierarchical cluster analys is grouped according to distance from river
117 Figure 3-2. Dendrogram of hierarch ical cluster analysis of presence/absence data for 108 amalgamated blocks. Data clustered us ing Bray Curtis Similarity Index with group average linkage on a reduced da ta set of plants found in more than one transect. Groups described at the 10% similarity level.
118 Figure 3-3. Dendrogram of hierarch ical cluster analysis of ground flora data for 108 amalgamated blocks. Data clustered using B ray Curtis Similarity Index with group averag e linkage on a reduced data set of plants found in more than one transect. Ground flora percentage cover data 4th root tran sformed prior to cluster analysis. Groups described at the 10% similarity level.
119 Figure 3-4. Dendrogram of hierarch ical cluster analysis of tree data for 84 amal gamated blocks Data clustered using Bray Curti s Similarity Index with group average linkage on a reduced data set of plants found in more than one transect. Tree data 4th root transformed. Groups described at the 10% similarity level
120 Figure 3-5. NMDS ordination map of presence/absence bloc k plant data. Outliers CAUL3 AROL1 AROL2, SOUU2, SOUM3, SOUM2, SOUU2, CAPM1 removed. a) Origin al block ordination, b-l) categorical and ordina l data superimposed on ordination maps, b) vegetation groups from cluster, c) geomorphologica l units, d) land ownership, e) riparian zone edaphic modification, f) upland edaphic modification g) channel modification h) form factor i) fire, j) pollution, k)canopy closure, l) distance from paved roads
121 Figure 3-5. Continued
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131 Figure 3-5. Continued
132 CHAPTER 4 A RIPARIAN CONSERVAT ION AND RE STORATION INDEX FOR TRINIDAD Introduction Human Impacts on Riparian Zones Riparian eco systems are subject to extensiv e disturbance as peopl e have traditionally settled along rivers for trans port and trade (Goodwin et al.1997; Freeman et al. 2003). In the United States, for example, Kentula (1997b) noted that approxim ately 90% of riparian corridors have been degraded. Disturbance may be due to direct or in direct influences. Direct effects include the clearing and replacem ent of riparian forest by agriculture, roads, buildings or levees. Recreationa l activities can result in vegetation trampling, removal of woody riparian plants for firewood, and construction of shelters, boat landings or trails. Remaining riparian vegetation may be grazed, trampled by livestock, or contaminat ed by agricultural or industrial chemicals (National Research Council 2002). Indirect impacts on riparian zones include alterations in hydrol ogy, and geomorphology of the ripa rian zone and associated watershed (Williams & Wiser 2004). These alterati ons can modify flood regimes and sediment delivery (Miller et al. 1995), re ducing spatial connectivity and a ltering the structure, composition and health of riparian vegetation (Karr 1981). Reduction in spatial conne ctivity of riparian vegetation can impede plant dispersal and move ment of animals along the riparian corridor (Naiman et al. 2005). Altered vege tation can also lead to impairmen t of riparian zone ecological functions such as nutrient cycling (Tabacchi et al. 1998). Human activities in the riparian zone also encourage the spread of exotic species at the expense of native species. A homogenous riparian flora dominated by exotic species may not be able to support diverse or abundant wildlife (National Re search Council 2002).
133 Riparian Restoration The negative consequences of ri parian degradation have spur red substantial in terest in riparian restoration. Restoration can be defined as reestablishing the structure and function of a system to return the habitat to a close a pproximation of their conditions prior to human disturbance (Williams et al. 1997). System rest oration involves replacing missing structural components such as native plant species and attemp ting to facilitate natu ral processes such as succession and nutrient cycling. Several authors ha ve emphasized that biological integrity should be a critical component and goal of restor ation (Angermeier 1997; Williams et al. 1997). Biological integrity refers to th e capability of supporting and maintaining a balanced integrated adaptive community of organisms, having a species composition, diversity and functional organization comparable to that of a natural habitat of the region (Karr & Dudley 1981). Williams et al. (1997) have; however, suggested that given the extent of anthropogenic modification of ecological systems, restoration to pre-disturbance levels is impractical. For instance, it may not be feasible to remove toxic sediments, or biologically impossible to replace extirpated species (Goodwin et al. 1997). Given the difficulty in establishing pre-dist urbance conditions, rest oration attempts are often focused on replacing some specific ecologi cal function of most benefit to humans. For example, Hyatt et al. (2004) de scribed riparian restor ation attempts in the Pacific Northwest, USA, where restoration procedures were sp ecifically geared towards increasing salmon populations in rivers. Salmon are partial to shad y pools, thus riparian re storation was focused on maintaining large riparian trees that shade the river and contribute large woody debris, which in turn creates pools. In restorati on attempts such as these, it is hoped that by re-creating the original structure, some aspects of the function of the ecosystem may be restored (Goodwin et al. 1997).
134 Effective restoration projects also require clear, functional, physical and ecological objectives, and an effective monitoring program to compare restoration outputs against appropriate reference systems (N ational Research Council 2002). One can try to remove some of the stressors, for example, livestock grazing on ag ricultural riparian land (Goodwin et al. 1997). There may be the need to eradicate exotics and replant native species. Other common practices in riparian restoration include rees tablishing fluvial landforms such as meanders and hydrological variables such as flooding regime (Bunn et al. 1998). However, in ur banized areas, reestablishing flooding regimes would not be possible, and removal of the stressor, i.e., human habitation is not usually an option. In these cases, re storation should be concentrated elsewhere, or there could be some mitigation attempts in the urba nized setting (Goodwin et al. 1997). Riparian restoration is difficu lt given the dynamic, complex nature of the riparian zone, the simultaneous impact of riverine and terrestrial influences, and the multitude of processes operating within the riparian zone. As a result, there is no one prescription for riparian restoration, and each site has to be assessed individually (Goodwin et al. 1997). For restoration to be successful, the site must be physically able to support riparian vegetation or else has to be manipulated to create suitable ab iotic conditions. In a ddition, riparian restoration has to take into account the larger spatial context, such as wate rshed influences on the riparian zone (Kentula 1997b). To increase the likelihood of a successful ripa rian restoration, it is sensible to identify the most suitable sites a priori Given possible financial and human resource constraints, a means of prioritizing these site s would also be beneficial. Riparian Indices Restoration sites can be desi gnated using a suitably design ed index as a decision m aking tool. Restoration indices are gene rally combined with conservation indices to identify sites that should be conserved, those that can be restored, a nd those that are so degraded that restoration
135 may not be worthwhile (Harris & Olson 1997; Russell et al. 1997). ONeill et al. (1997) emphasized the need for these types of indices suggesting that for t oo long, riparian zone management has been taking place without this important evaluation. Index design varies depending on specific cons ervation and restorati on goals. Goals may range from improving water qualit y by riparian sediment retenti on, to improving riverine fish stocks, to providing wildlife corridors for large ma mmals. A riparian area, restored for sediment retention, may be of a different width or speci es composition to an ar ea restored for wildlife habitat (Hawes & Smith 2005). Consequently, a conservation or restoration index should have different variables and cutoff points, depending on conservation and restoration goals. Index design may also differ depe nding on available resources, for example, funding and labor. However, indices should be simple, expedient, flexible and have general applicability to allow modification to suit local conditions (O'Neill et al. 1997). Innis et al. (2000) also advocate common sense and the need to avoi d complex unrealistic methods. Riparian indices generally a ssess site biological integrity, physical characteristics and levels of anthropogenic disturba nce. Biological or ecological integrity indicators can include wildlife parameters such as butterfly presence/absence (Nel son & Andersen 1994); however, riparian vegetation characteristics are more commonly used (Landers 1997). Anthropogenic indicators suggest th e potential success of conservati on and restoration depending on how defensible a site may be against current and future human intervention. Thus, Kittel et al. (1999) included indicators such as fire and la nd use history in their assessment of riparian vegetation in Colorado. Similarly, Salinas et al (2000) measured the types and intensity of human impacts for each site they assessed. Phys ical variables include flooding regime and soil wetness. For example, Russell et al. (1997) de vised a composite riparian index based on soil
136 moisture, land cover and position in the watershed. Wh ile riparian reach characteristics appear to be most often used in riparian integrity indices, there is also recogni tion of the utility of catchment scale measures as indicators of ri parian integrity (Kentula 1997b; Landers 1997). Overall, it appears that indices rely on a wide ra nge of measures to provide a holistic picture of a sites conservation and restoration potential. Ex amples of riparian indi ces are provided in Table 4-1 including general methodologies, scoring systems and validati on techniques. Table 4-2 lists and categorizes the indicators used in the riparian index litera ture in Table 4-1. As studies on tropical island ri parian zones are lacking, so too are means of assessing the biological integrity of riparian sites and their suitability for re storation and conservation. From a theoretical perspective, it would be useful to assess common riparian indicators for applicability in tropical island riparian zones. From a pract ical perspective, given the level of degradation along rivers in Trinidad as outli ned in Chapters 2 & 3, a suitable index could jumpstart riparian restoration and conservati on efforts on the island. Objectives The goal of this Chapter is to develop and test an index to determ ine and prioritize riparian sites for conservation and restoration in Trinidad Indices vary depending on available resources and specific restoration objectives. Thus, for this study, the following goals and boundaries will be followed: The index will be designed to assess sites for conservation or restoration for improving river water quality via ri parian nutrient absorption and se diment retention. It will assume a 30 m buffer width, which was determin ed as the active riparian zone width for Trinidad, and is the width recommen ded for sediment retention by others, for example, Wenger (1999). The index will assume that the more simila r a site is to reference riparian conditions, the better able it is to maintain ecological functions such as sediment retention, nutrient absorption and provision of wildlife habitat. The index wi ll also assume that people carrying out the
137 assessment may not have strong plant taxonomic sk ills, but can be trained to recognize key indicator plants. In addition, the index will be a rapid assessment technique utilizing a minimum number of pertinent, easily measurable variables. Index limits outlined above are based on what might be practical and feasible in Trinidad. There are currently no riparian buffer strips desi gnated under Trinidadian law; however, there is some interest by the Water Resources Agency to establish them (Water Resources Agency pers comm.). The absence of national riparian buffer regul ations is one constraint to consider in the design and implementation of riparian restoration schemes in Tr inidad. In the absence of pertinent regulations, narrow buffers may be more feasible. If riparian buffers were legislated, a narrower buffer would be easier to enforce. A narrow 30 m buffer can serve its sediment retention function, but at the same time, confer some protection to terrestrial and aquatic wildlife. The other constraint in designati ng and choosing areas to restore or conserve is the length of the buffer along a stream. Generally, it is recomm ended that buffers be continuous to avoid channelized runoff into rivers through riparian vegetation gaps (Hawes & Smith 2005). It may not be possible to have continuous buffers over long distances along rivers, but perhaps it may be feasible in certain key areas. Methods Literature Review Riparian literature was reviewed and assessed fo r general trends regard ing riparian indices, format, design and suitable rapid assessment te chniques. One hundred and six papers were examined. Riparian index review papers, for example, Kentula (1997a) & Inni s et al. (2000) were especially useful in this study. Vegetation based index papers were emphasized as plant indicators are more frequently used than wildlife indicator s (Landers 1997). Wetland index papers were excluded following Innis et al. (2000), who suggested that wetland and riparian
138 ecosystems should be treated separately. Papers wher e riparian assessments were part of a larger riverine assessment were also excluded; focusi ng instead on papers where riparian health assessment was the end point. General Methodology The index was based on vegetation and abiotic param eters using methods and indicators derived from the literature and data gathered from a study of riparian vegetation and its determinants in Trinidad. Results from the Tr inidad study are presented in Chapters 2 & 3, and summaries of index methods and indicators from the literature are provided in Tables 4-1 and 4-2. The formulation of the index drew heavily from Innis et al. (2000), who outlined a hierarchy of steps for conducting riparian ecological assessments. These authors recommended an initial ecological inventory, fo llowed by classification of the data collected, then identification of indicators and finally, ecologi cal assessment (Figure 4-1). An inventory provides detailed information on the biological, physical and anthr opogenic characteristics of a site. Classification groups sites on the basis of comm on features. Indicators are selected to capture and represent a wide range of site information. Assessments co mpare indicator values amongst sites or against some predefined reference condition. In the pape rs described in Table 4-1, reference conditions were assigned on the basis of specific ve getation types, minimal or no anthropogenic disturbance, or the authors professional judgm ent. Index variables outlined in Table 4-2 were delineated using information from detailed inve ntories, indicators from other assessments or literature on plant characteristics. These general trends were retained for the Tr inidadian riparian index. To make the index more robust; however, the following modifications were incorporated: 1) The index used three types of indicators: biologi cal, physical and anthropogenic variables merged into one
139 comprehensive index to provide the best possible assessment of the site. 2) Information from riparian site inventories and th e classification exercise for Trinidad were used to establish reference conditions, and also to make management decisions as to which of the sites should be conserved, restored or left as is. 3) Abiotic and anthropogenic variables iden tified in the literature for potential use in the index, al so had to be statistically signi ficant determinants of riparian vegetation groups in Trinidad. Inventory, Classification and Esta blishment o f Reference Conditions Thirty-six sites were inventoried with regard to their biological (veg etative), anthropogenic and environmental characteristics. These data we re recorded along 3, 30 m transects at each site, as described in Chapter 3. At each site, plant species composition, tree species importance value and ground flora percentage cover were noted. Reco rds from the National Herbarium of Trinidad and Tobago (TRIN), described in Adams & Ba ksh-Comeau (Unpublished) were used to determine species habitat preferences and traits. It was noted whether plants were previously recorded along rivers, in wetlands or in moist ar eas, or if they were commonly found in forested areas. It was also noted if they were natives or exotics. Site anthropogenic characteristics like evidence of recreation, edaphic modification, fire and distance from roads were recorded, as well as environmental variables like river discharge. Th ese site details have been provided in Chapters 2 & 3. Vegetation classes were deli neated using cluster analysis of 108 sample blocks at the 36 sites sampled. Riparian group composition was comp ared to historical data (Beard 1946) to assess similarity to natural state vegetation for specific geographic locales. Sites with natural state vegetation were designated as reference sites and also potentia l conservation sites, especially if there was little anthropogenic disturbance. Sites with weedy, agricultural or disturbed vegetation groups, for example, fire impacted vegetation were not recommended for
140 restoration or conservation. A decision tree for determining management strategies based on inventory and classification data is provided in Figure 4-2. Indicators The m ost common biological variables (Table 4-2) were used for the Trinidad index, provided they were easy to measure and calculate (Figure 4-3). Frequently used defensibility and physical integrity indicators were also used, provided they were statistically significant determinants of riparian vegetation groups in Trinidad. Statistical sign ificance was determined by a rank correlation method where 43 environm ental and anthropogenic variables were subjected to BVSTEP and BIOE NV analyses in the software program PRIMER to assess the relationships between vegetation cl usters and potential explanatory variables. PRIMER routines superimposed an environmental similarity matr ix onto a vegetation similarity matrix, providing the best combinations of explanatory variable s, which produced the highest rank similarity ( ) between the plant and environmental matrices (Clarke &Warwick 2001). Details are provided in Chapter 3. Figure 4-4 outlines the overall decision-making process for selecting index parameters. Variables were repeatedly added and discarded until the smallest number of easily measured, effective discriminating variables was achieved. Index Design and Validation The index was designed and tested so that when it was utilize d in the field, the indicators would provide the same management suggestions as the detailed inventory and classification process, but with substantially less work. Three possible management options were designated for both the index and detailed analyses, na mely, conserve, restore or no action. Sites recommended for conservation were also potential riparian reference sites and warranted some level of protection even in the absence of legisl ated riparian buffers. Conservation sites were
141 characterized in the inventory and classification stage by natural state vegetation type and minimal anthropogenic activity. In the index, rapidl y assessed indicators were used instead to represent the high biological in tegrity of natural state vege tation sites and low biological integrity of degraded sites. It was assumed that if biological integrity was high, the hydrological regime and physical integrity were intact. The most defensible conservatio n sites were assigned a higher priority for conservation. Sites which had high biological integrity but were threatened by current or potential future human activity (less defensible) had a lower conservation priority. In the inventory and classifi cation phase, no action si tes were either those with agricultural or fire influenced vegetation types or sites in de veloped areas. These were also physically unsuitable for restoration, for example, impaired flooding regime through channel modification. Restoration site s required removal of threats, for example, grazing or exotic species or replanting of natives. Restoration was consid ered worthwhile if there was a high number of native species. In the index, no ac tion sites had low biological integrity and low defensibility. The more defensible the site, the higher the restor ation priority. In the in dex, restoration sites fell between the no action and conser vation sites in terms of biologica l integrity and defensibility. Priority was assigned by highest scores in biological integrity, physical integrity and defensibility categories. Scoring followed schemes from the literature focusing on simple additive methods without the need for co mplex and time consuming observations and calculations. For validation, th e index was designed using the 12 sites from the North Geomorphological Unit and tested using the 12 sites from the South Geomorphological Unit. This followed the general approach in the literatu re, where indices were va lidated using different geographic locales (Table 4-1).
142 Results Literature Review Riparian ass essments and associated indicators have been highlighted in Tables 4-1 and 4-2. The 35 indicators in Table 4-2 were categor ized into five defensibility, 22 biological, six physical and two biogeochemical indicators. Biogeochemical integrity indicators assessed riparian zone functioning. The most frequently used indicator was a defensibility parameter, namely land use/disturbance followed by channe l morphology, a physical integrity parameter. The most frequently used vege tation indicator was structure, for example, number of vegetation layers. The scoring techniques highlig hted in Table 4-1 were both qualitative and quantitative. Where quantitative systems were used, they were generally simple and additive. Jansen & Roberston (2001) & Petersen (1992) weighted va riables differently depending on what they considered to be most important indicators. Inventory, Classification and Vegetation Determinants The following vegetation groups were delineated from cluster and correlation analyses: Eschweilera subglandulosa Justicia secunda (North Forest) Mora excelsa-Bactris major (South Forest) Saccharum officinarum (Agriculture) Axonopus compressus (Agriculture), Bambusa vulgaris Flemingia strobilifera (Fire Influenced), Sorghum sp. (Weedy Species), Justicia secunda (Secondary Vegetation) and Acroceras zizanioides (Native Grasses). The best predictors of riparian vegetation groups were canopy closure, degree of up land and riparian zone edaphic modification, geomorphology, fire, channe l modification, distance from paved roads, land ownership, pollution and form factor. See Tables 3-2 to 3-7 in Chapter 3 for details on these groups and their significant predictors. The Eschweilera subglandulosaJusticia secunda and the Mora excelsa-Bactris major groups had few exotic species and were associated with unmodified
143 river channels, low levels of edaphic modification, high canopy cl osure and an absence of fire. They were also located far away from paved ro ads. Given the similari ty of their vegetation composition to Beards (1946) descri ption of natural state vegetation and the absence of fire and channel modification, sites with these vegetation types were r ecommended for both conservation and as reference sites (Table 4-3 and Figure 4-2). The Axonopus compressus and Saccharum officinarum agricultural groups were associated with channel modification. The S. officinarum and F. strobilifera groups were associated with fire. Sites with these vegetation type s were recommended for no action. The Sorghum sp. group consisted of weedy species. It was recommended for no action if it was found in areas with fire, concrete structures or pa ved areas (Table 4-3 and Figure 4-2). Sites in the Justicia secunda (Secondary Vegetation) group were found mostly in abandoned agricultural estates and allocated as pote ntial conservation areas, especially if they were in an advanced state of regeneration and had riparian or wetland species as described in Adams & Baksh-Comeau (Unpublished). The Acroceras zizanioides group was dominated by native grass species. It was recommended fo r conservation provided human interference, for example, fire and edaphic modifi cation was minimal. The Bambusa vulgaris group, while characterized by an exotic grass, was recommende d for conservation if there were native plant species, no evidence of fire and limited edaphic modification (Table 4-3 and Figure 4-2). Overall out of 24 sites assesse d, 11 were recommended for conservation, seven for no action, and six for restoration. Indicators The biologic al integrity variable s used were the number of trees and the presence/absence of the following species: Bambusa vulgaris Sorghum sp., Pureria phaseoloides Cecropia peltata Ochroma pyramidale Heliconia bihai/spathocircinada Spondias mombin and Hura
144 crepitans (Appendix J). Fire was used as an anthropoge nic/site defensibilit y variable. It was weighted negatively, as fire can modify or comple tely destroy riparian vegetation. Also recurring fires can hamper restoration attempts. Disturban ce was the other anthropogenic/site defensibility variable. This variable was a combination of vegetation group, level of edaphic modification and canopy closure. It was further divided into upland and riparian zone disturbance. Index variables are highlighted in Appendix J, which also provides the format and instructions for using the index in the field. Index results for North Unit sites are shown in Table 4-4. The index recommendations for these sites match those of the detailed inventory and classification results (Tables 4-3, 4-4). The results of the validation exer cise using South Geomorphological Unit sites also match the recommendations from the detailed analyses (Tables 4-3 and 4-5). It thus appears that the index is suitable for use throughout Trinidad. Overa ll, four sites in the Northern Range were demarcated for conservation, six for restoration, while no action was recommended for two sites. Index validation using the Sout hern Geomorphological Unit resu lted in six sites recommended for conservation, one for restorat ion and five for no action. Discussion Suitabliltiy of Metrics Of 35 potential indicator variables identified (Tab le 4-2), only eight vari ables were utilized in the index as these were adequate to discrimina te between sites, as we ll as being quick and easy to measure. Additionally, they we re significant determinants of ri parian vegetation in Trinidad. No more variables were necessary, and this index follows other compact indices, for example, Part et al. (2003) who utilized four variables in their index. The first biological integrity variable chosen was tree species richness. Site diversity was also tested, but richness adequate ly segregated the sites withou t additional data collection and
145 calculations needed for diversity measurements Diversity and species richness are common riparian indicators (Table 4-2). Trees were used instead of ground flora, given an overall low number of trees at the sites st udied, which meant that less time was needed to count the number of tree morphotypes. Tree species richness was a good discriminant for all vegetation groups, as sites with agricultural and sec ondary vegetation had either monoc ultures or a few agricultural species resulting in a lower biological inte grity compared to forest sites. Percentage exotic species was another commonly used index variable but was not used for this index because it would be time consuming to identify and count the large number of riparian exotic species found in Trinidad (49 species as noted in Chapter 2). Inst ead, easily recognizable exotic species such as B. vulgaris Sorghum sp. and P. phaseoloides were singled out as poor biological integrity indicators. Ot her easily identifiable species were also used in the index including the secondary vegetation species C. peltata and O. pyramidale An abandoned agricultural estate with a high abundance of these species suggests a long period of agricultural abandonment regression towards hist orical riparian conditions. Abandoned agricultural estates with a high abundance of secondary indicator sp ecies were, therefore, considered potential conservation sites in this study. Forest group species were not utilized in this index, as they are difficult to identify. Also, with the exception of the Mora forests in s outh Trinidad, forest species consisted of few individuals distributed across a la rge number of species. In add ition, it appeared that riparian plants could include generalist forest species as desc ribed in Chapter 3. Thus, trying to pinpoint riparian forest species would not be practical. Furthermore, there were differences in forest species amongst geomorphological units in Trinida d. For example, south forest species included Mora excelsa which was not encountered in the North or Central Geomorphological Units. On
146 the other hand B. vulgaris was found across all geomorphological units. The most frequently used biological integrity indicator in Table 4-2, vegetation structure, was represented in this index by tree species richness. Fragmentation indicators, although commonly used (Table 4-2), were not utilized in this study due to unavailability of relia ble spatial data. The site defensibility indicators used were fire and disturbance. Fire can destroy riparian vegetation or riparian species can be replaced by more fire tolerant species (Bendix 1994; Naiman et al. 2005). It is di fficult to defend against and was heavily negatively weighted. Attempting restoration and conservation in fire prone sites is not wort hwhile unless biological integrity is extremely high. The disturbance vari able (the most commonly used variable in Table 4-2) attempted to quantify human in terference at riparian sites (exclu sive of fire). It was based in part on edaphic modification, wh ich was a significant determinan t of riparian vegetation in Chapter 3 and included aspects like soil compacti on, the presence of beds and furrows, and the presence of paved or concrete areas. Disturbance also included vegetation type and canopy closure components. Sites with agricultural grou ps or low canopy closure were representative of more human interference and degraded condtions (Appendix J). The only physical integrity indicator used was channel modification. Other potential physical variables like soil parameters were not utilized as they were not significant determinants of riparian vegetation (Chapter 3). Modified ch annels (resulting mostly from dredging in Trinidad) reduces flooding in riparian areas (Wissmar & Beschta 1998; National Research Council 2002). Although beneficial for sett lement and agriculture, reduced flooding is deleterious to riparian vegetation growth. At agricultural sites, it may be possible to restore hydrology by bank modification, but this may not be justifiable in terms of the time and labour needed and perhaps restoration should be concen trated in areas with intact channel morphology
147 and hydrology. Sites in agricultural areas, which were dredged long ago and are unlikely to be dredged in the future, could be considered rest oration sites. This is because, over the years channels may have filled in, and deposition may have reduced bank gradients, increasing the likelihood of a natural flooding regime. As a resu lt, sites with dredging had a low restoration priority. Kentula (1997b) pointed out the utility of mu lti scale variables incl uding watershed level variables in riparian integrity indices. Watershed landscape metrics (percentage catchment forest cover) was not a good predictors of riparian ve getation groups in Trinidad (See Chapter 3) because of much stronger relationships with reach level factors like fire and channel modification. Hence, watershed variable s were not utilized in the index. Index Design, Validation and Constraints Variables utilized in the index were rapid visu al assessments such as presence/absence of certain species or evidence of specific human ac tivities. Variables requiring observer estimations were not used to reduce assesso r variability in carrying out th e assessment. Vegetation and environmental data were derived from 30 m2 sample blocks. This area can be retained for the index, given that variables used needed only rapi d visual evaluations. Th e scoring scheme was a simple additive method; no lengthy calculations were needed. Priority for restoration and conservation was assigned based on higher scor es in each category (O'Neill et al. 1997). The index is flexible, allowing for the addi tion of other criteria as circumstances necessitate (Oetter et al. 2004). The valida tion exercise using sites in the South Geomorphological Unit showed that it was possi ble to differentiate among south sites using metrics derived from the north sites. For example, the index suggested that the Moruga River sites were high priority conser vation sites, as did the more detailed classification inventory exercises (Table 4-3).
148 This study focused on identifying appropriate va riables and a rating scheme for use in a rapid riparian conservation and re storation assessment. The next step should be testing the suggested protocol (Appendix J) to assess the time needed to carry out the assessment and determine how user-friendly it is. Field-testing would also identif y modifications to reduce interperson variability in data collec tion Prat (2003). The index can serve as a baseline and more elaborate work including taxonomic analyses can solve any site specific dilemmas (Ward et al. 2003). The index was designed for Trinidad but can be modified and applied to other Caribbean islands depending on their riparian species co mposition and determinan ts. Additionally, the index can be used to monitor effects of restoration and conservation measures (Dixon et al. 2005). Tropical Island Context There is lim ited literatu re on island riparian vegetation, and by extension, limited examples of island riparian indices. Gene ral metrics suggested by the literature appear relevant to small islands as well, as demonstrated by this study. Given the small size of rivers in Trinidad (Chapter 2), variables applicable to small streams in te mperate areas were relevant. For example, one variable used in the index was disturbance beyond the riparian zone. Peterson (1992) used upland land use as a variable in the Riparian Channel and Environmental Inventory (RCE) index (Table 4-1) as it was a determinant of ripari an vegetation along small streams. Land use beyond the riparian zone also indicates connectivity to natu ral ecosystems (Peterse n 1992; Kittel et al. 1999). Overall, it appears that parameters and me thodologies used in ripa rian indices worldwide are also applicabile to tropical islands. Restoration Techniques This study does not provide a blueprint for ripari an restoration in Trinidad. The index just seeks to ide ntify places that shou ld be conserved and places wher e restoration is likely to be
149 successful. However, riparian vege tation characteristics and determ inants suggest some factors, which should be considered in any restoration at tempt in Trinidad. This index was designed to aid in riparian management decisions for improved river water quality and to a lesser extent wildlife and biodiversity protecti on. Thus, suggestions for restoration are geared towards these goals as well. High biological integrity sites are more capable of supporting ecosystem functions (Karr & Dudley 1981). In the case of riparian zones, th is can include nutrient absorption and sediment retention, which are important aspects for ri ver water quality (Pet erjohn & Correll 1984; Anbumozhi et al. 2005). Proposed conservation areas could be left as is for biodiversity purposes, assuming the functions of sediment and nutrient retention are adequately maintained under natural vegetative conditions. However, in agricultural areas marked for restoration, it may be more practical to focus on replanting select species, which through further experimental work may be identified as fast growing or useful for nutrient and sediment rete ntion. This type of restoration may be particularly useful at sites close to water extr action points. Restoration geared towards biological integrity could be relegated to areas where water quality is not as critical or where there may be a greater need to protect the site for riparian wildlife or plant biodiversity. For restoration, there may be the need to eradicate exotics and re plant native species especially if biological integrity is a primary goal. The pr evalence of exotic bamboo along rivers in Trinidad would then warrant sp ecial attention. It is fast gr owing, aggressive and difficult to eradicate (McClure 1993). It may be that given feasibility, tim e or financial constraints, bamboo could be left in place at low priority, less defe nsible restoration sites. Additionally, given the plants dense matted root network, leaving bamboo along rivers can be justified for sediment retention and bank stabili zation. Bamboo has in fact been pl anted along rivers in Trinidad for
150 bank stabilization purposes (Forestry Division pers comm.). A higher priority for bamboo removal may be in upper river reaches, as the pl ant can reestablish itself from broken culms transported downstream (O'Connor et al. 2000). Common practices in riparian re storation include rees tablishing fluvial landforms such as meanders and hydrological variables such as fl ooding regime. Accumulated sediment may have to be removed (Bunn et al. 1998). In the Trinidad c ontext, this may not be practical as the areas where hydrology and geomorphology have been altered are close to human habitation or agricultural areas. However, hydrology and geomorphology can perhaps be restored in abandoned agricultural areas. River Management The index designed in this study is specific to riparian zones. However, riparian restoration and m anagement are often tightly linked to ri ver restoration (Peterse n 1992; Goodwin et al. 1997). This index can be utilized as a component of a river management index, which may also incorporate water quality and aquatic fauna i ndicator species. Aquatic variables may also identify areas where riparian restoration is urgently needed. Some ripari an restoration decisions become more complicated within the larger contex t of river restoration. Fo r example, the plants used in riparian restoration would have to be considered in terms of their impact on aquatic wildlife, for example, if they would be a good food source for riveri ne species. Both riparian and river management should also be considered in terms of overall watershed management. Kentula (1997b) & Landers (1997) advocate a watershed approach to ripari an restoration recognizing the control that watershed processes and spatial char acteristics have on riparian ecosystems (Allan et al. 1997).
151 Table 4.1. Examples of riparian assessment me thodologies, applications, scoring and validation methods Index summary Scoring and validation methods Innis et al. (2000) reviewed riparian index papers and suggested their own indicators of ecological integrity. Their positive indicators were: in creasing levels of canopy development, biodiversity, microclimate, river seston and patch heterogeneity. Incr easing terrestrialization was seen as a negative indicator. They also outlined a hierarchy of information for conducting eco logical assessments moving from detailed inventories, to classification, to the derivation of indicators and finally the highest level ecological assessment. Only outlined their suggested variables, no mention of validation or scoring. Kittel et al. (1999) ranked sites using indicators of 1. Quality: vegetation patch sizes, connectedness to natural ecosystems, degree of stream flow alteration. 2. Condition: number of exotic species, soil compaction levels, livestock grazing, amount of human disturbance, stand age, species composition and water quality. 3. Viability: hydrological regime integrity and current site management. 4. Defensibility: site threats, factors affecting the site survival. Subsequent revision of the index after two years extended the parameters to include: 5. Landscape context: adjacent land use, habitat fragmentation, watershed hydrology changes, activities immediatel y outside the riparian zone. 6. Overall size of vegetation patch, and size relative to presettlement conditions. Sites were compared to reference conditions, which the authors based on professional judgment. Riparian health was calculated as the average of quality, condition, viability and defensibility, landscape context and patch size indicators, and then ranked from the highest A to the poorest D. An A ranked site possessed characteristics like: few exotics, limited soil compaction, riparian vegetation connected to surrounding vegetation and limited human activity in the watershed. A ranked sites were recommended for protection.
152 Table 4.1 Continued Index summary Scoring and validation methods Dixon et al. (2005) developed the Tropical Rapid Assessment of Riparian Conditions (TRARC) for tropical savannah areas in Australia. The TRARC used 21 riparian zone function indicators (Naiman & Decamps 1997) to delineate sites for conservation and restoration and to judge the success of these types of activities. Indicators were divided into five categories, i.e. cover, debris, natives, regeneration and disturbance. Johansen et al. (2007) compared the TRARC field based approach to a remote sensing approach (Quickbird imagery). The two approaches were found to be complementary. Remote sensing methods were recommended for coarser scale analysis fine tuned by the TRARC field methods. Each of the 21 indicators were given a score from 0-4. For example for ground cover: no ground cover=0, 1-30% ground cover=1, 30-60% ground cover=2, 60-85% ground cover=3 and 85-100% ground cover=4. Indicators such as number of juveniles in the understory scored double highlighting the importance ascribed by the authors to regeneration as a biological integrity indicator. Final score was calculated as the sum of all indicators out of a maximum of 100. Jansen & Roberston (2001) described a rapid appraisal method focusing on the effect of grazing on the riparian zone. Physical, biological and landscape indicators were used, grouped within six genera l categories i.e. cover, bank characteristics, natives, debris, habitat and species characteristics. Used reference sites in relatively pristine sites. Scores ranged from 0-50. Variables were weighted, for example, the woody debris category could capture a maximum of 10/50 points while natives only 5/50. Salinas et al. (2000) evaluated the degradation state of riparian vegetation in south-east Spain. Positive indicators included evidence of regeneration, plant percentage cover and species richness. The number of exotic species was used as a negative indicator. Human impact intensity was also noted. The index was designed to show the most degraded sites and those needing restoration. No validation method presented. Degradation level based on sum of the values assigned to each indicator. Prat (2003) outlined the Qualitat del Bosc de Ribera (QBR) index to measure riparian ecological integrity. Partly based on Petersen (1992), variables included total vegetation cover, vegetation quality, ve getation structure and channel modification. High scoring sites had complex vegetation structures, high species richness and little or no channel modification. The index was found to be applicable to different regions in Spain. The index was developed in Catalonia, Spain, tested using 72 sampling sites and validated at sites along the Mediterranean Spanish coast. Each variable was worth a maximum of 25 points and the total possible score was 100.
153 Table .4-1. Continued Index summary Scoring and validation methods Simon (2001) developed a rapid multi-metric biotic integrity assessment for riverine we tlands following Karr (1981), using plant variable substitutes for Karrs fish indicators. Variables included number of individuals of indicator plant species, for example, Carex and Potamogeton number of emergent species, number of perennial species and number of sensitive plant species. The higher the score for these variables the greater the biological integrity and closer to reference conditions. The higher the number of exotic species, and the greater the number of plant abnormalities, for example, rust and lesions, the lower the biological integrity. No validation only initial set of variables presented for further testing. Metrics were used to produce an overall score between 1-5 with 5 being the best site score. Fry et al. (1994) outlined the Riparian Evaluation and Site Assessment (RESA), which ranked sites according to functions and benefits. This was a rapid assessment based on the US Soil Conservation Service Land Evaluation and Site Assessment (LESA). Biological, physical and anthropogenic parameters were used. No validation method stated. Scored using a simple additive method. Oetter et al. (2004) used a GIS approach to prioritize restoration sites based on land cover, channel modification and floodplain vegetation. Sites with lower levels of development and relatively complex channel and vegetation structures were recommended for restoration. No scoring provided just developed relevant GIS layers. O'Neill et al. (1997) used GIS to characterize geomorphology, hydrology, relative soil moisture, disturbance (stream energy), land use and vegetation to determine site restoration potential. Parameters scored from -2 to +6. Highest scoring sites were assigned as priority restoration areas. The method was tested using two field sites. Russell et al. (1997) used a GIS approach to identify potential restoration sites using wetness and land use classes. Wetness was determined from Digital Elevation Models. Areas with high/medium wetness and natural vegetation were allocated for preservation. Agricultural and barren sites with medium wetness were designated for restoration. Restoration priority was based on proximity to existing riparian vegetation areas and size of the existing patch. No scoring or validation, just developed GIS layers.
154 Table 4.1. Continued Index summary Scoring and validation methods Petersen (1992) developed Riparian Channel and Environmental Inventory (RCE) for small streams. This was a rapid semi-quantitative method with weighted metrics. Variables included land use, vegetation characteristics and channel morphology. The total score (maximum of 360) was used to assign status and prescribe management actions. For example a site scoring between 293-360 was considered in excellent condition and recommended for protection. A score of 86-153 was deemed a site in fair condition with major alterations needed. The index was designed for agricultural settings and tested under alternative land use categories. The authors allotted higher weights (maximum of 30) to variables like riparian zone completeness as opposed to riparian zone plant density (maximum of 25 points). Ward et al. (2003) described a simple visual riparian health assessment method. Variables included flooding regime and bank stability. This technique deviated a bit from other methods as it included stream integrity characteristics, for example, fish and macro-invertebrate habitat to assess riparian health. Score was the sum of either 12 or 6 points per variable. Bank stability, for example, was weighted lower (maximum of 6 points) than flooding regime (maximum of 12 points). Coles-Ritchie et al. (2007) assessed ecological integrity using average weighted scores based on community classes following Winwards (2000) vegetation classification. Sites with hydric vegetation classes scored higher. Calculated a site wetland index based on community type. For example, a plant community with only obligate wetland species scored 100 and a community type with only upland species scored 0. The site wetland index was calculated based on the percentage of each community type at each site. Hauer & Smith (1998) and the more detailed Hauer et al. (2002) assessed sites using indicators of riparian zone function, compared to reference conditions. Functions were divided into hydrological, bi ogeochemical, vegetation and faunal maintenance categories. The index was used to assess sites before and after impacts, in restoration planning and to monitor restoration efforts. Scoring was based relative to reference systems. Numerous calculations were required for this functional index.
155 Table 4.1 Continued Index summary Scoring and validation methods Harris & Olson (1997) prioritized riparian areas for protection and restoration by combining coarse scale remote sensing techniques with fine scale field methods. In the first stage aerial photos and maps were used to rank sites on the basis of land use. Sites with > 30% urban or agricultural land cover were eliminated as potential restoration or protection sites. Possible restoration sites were identified on the basis of 60-90% riparian cover, low fragmentation and <10% agriculture or urban land use. Potential restoration sites were visited in the field and assessed in terms of geomorphology and their associated vegetation communities, then compared to reference conditions. Reference conditions were selected based on the authors professional judgment and indicators selected which characterized the reference conditions and by extension distinguished between the high integrity reference conditions and other sites. Validation via application to riparian areas in southern California as described in Olson & Harris (1997). A specific scoring system was not provided.
156 Table 4-2. Most commonly used fiel d indicator variables from Table 4-1 Variable type Variable No. of times used Biogeochemical Water quality 2 Biogeochemical Nutrient cycling/nutrient export/organic matter export/organic matter decomposition/particulate retention 1 Biological integrity % bare ground 1 Biological integrity % canopy ju veniles in the understory 1 Biological integrity % grass cover 1 Biological integrity % ground cover 2 Biological integrity Abundance of a speci fic indicator species or vegetation community type/species composition 5 Biological integrity Biodive rsity/species richness 4 Biological integrity Canopy coverage/% shading/overstory cover/canopy continuity 3 Biological integrity Evidence of plant regeneration/% canopy juveniles in the ground flora 3 Biological integrity No./ % of exotic species 5 Biological integrity No. of native species/native plant coverage 3 Biological integrity Patch conne ctivity/floodplain habitat connectivity/fragmentation/completeness of riparian zone 7 Biological integrity Plant % covera ge/total vegetation coverage 4 Biological integrity River seston 1 Biological integrity Soil organic material/thickness of each horizon layer/soil structure 2 Biological integrity Vegetati on patch heterogeneity 1 Biological integrity Vegetation pa tch size/riparian zone width 3 Biological integrity Vegetation qualit y, for example, rust and lesions 1 Biological integrity Vegetation stand age 1
157 Table 4-2. Continued Variable type Variable No. of times used Biological integrity Vegetation structure, for example, presence or absence of trees/variation in structure/density/ability to maintain characteristic plant community structure/tree density/shrub coverage/herb coverage/no of vegetation layers 7 Biological integrity Wildlife/riparian zone wildlife habitat/in stream aquatic habitat 3 Biological integrity Woody debris incl uding: fine woody, coarse woody and standing dead/detrital biomass/large woody debris/aquatic woody debris. 3 Defensibility Adjacent land use/upland land use 3 Defensibility Amount of human disturbance/long-term site viability/site management practices/intensity of human impacts/recreational use/riparian zone land use/degree of development/land cover type 11 Defensibility Animal impact 1 Defensibility Fire impact 2 Defensibility Watershed integrity including:% natural forest/% agriculture/proportionality of landscape features 3 Physical integrity Channel morphol ogy/channel structur e/evidence of slumping/gully erosion/bank stability 9 Physical integrity Degree of soil compaction 1 Physical integrity Degree of st ream flow alteration/channel modification/geomorphic modification 4 Physical integrity Degree of terrestrialization 1 Physical integrity Intactness of hydr ological regime/surface and subsurface flooding/surface and subsurface water storage (groundwater) 4 Physical integrity Soil moisture level 1
158 Table 4-3. Recommended site management strategies based on detailed taxonomic and classification analyses Geomorphological Unit Site Site Acronym Management Strategy N orth Aripo Lower Reach ARIL Restore N orth Aripo Middle Reach ARIM Restore N orth Aripo Upper Reach ARIU Conserve N orth Arouca Lower Reach AROL Restore N orth Arouca Middle Reach AROM Restore N orth Arouca Upper Reach AROU Conserve N orth Caura Lower Reach CAUL N o action N orth Caura Middle Reach CAUM Conserve N orth Caura Upper Reach CAUU Restore N orth N orth Oropouche Lower Reach N ORL Conserve N orth N orth Oropouche Middle Reach N ORM N o action N orth N orth Oropouche Upper Reach N ORU Conserve South Moruga Lower Reach MORL Conserve South Moruga Middle Reach MORM Conserve South Moruga Upper Reach MORU Conserve South Penal Lower Reach PENL Conserve South Penal Middle Reach PENM Conserve South Penal Upper Reach PENU N o action South Poole Lower Reach POOL Conserve South Poole Middle Reach POOM Restore South Poole Upper Reach POOU N o action South South Oropouche Lower Reach SOUL N o action South South Oropouche Middle ReachSOUM N o action South South Oropouche Upper Reach SOUU N o action
159Table 4-4. Index results for sites in the North Geomorphological Unit Site Rating according to no. of trees Bambusa presence/ absence Sorghum / Puereria presence/ absence Secondary species presence/ absence Disturbance Disturbance 50-100 m from the river channel Evidence of fire Biological integrity subtotal Site defensibilit y subtotal TotalManagement recommendatio n ARIL 2 10 0 0 3 10 50 12 63 75 Restore ARIM 4 10 0 5 2 2 50 19 54 73 Restore ARIU 6 10 5 5 10 2 50 26 62 88 Conserve AROL 0 10 0 0 3 0 50 10 53 63 Restore AROM 4 0 2 0 6 6 50 6 62 68 Restore AROU 6 10 2 5 6 6 50 23 62 85 Conserve CAUL 2 0 5 0 0 0 0 7 0 7 No action CAUM 6 0 5 0 10 10 50 11 70 81 Conserve CAUU 4 0 2 0 6 6 50 6 62 68 Restore NORL 6 0 2 5 6 2 50 13 58 71 Restore NORM 2 0 2 0 3 3 0 4 6 10 No action NORU 10 10 5 0 10 10 50 25 70 95 Conserve Key >80 Conserve, 50-80 Restore, <50 No action
160Table 4-5. Index results for sites in the South Geomorphological Unit Site Rating according to no. of trees Bambusa presence/ absence Sorghum / Pureri a presence absence Secondary vegetation species/abs ence Disturb -ance Disturbance 50-100 m from the river channel Evidence of fire Biological integrity subtotal Site defensibility subtotal TotalManagement recommendation MORL 6 10 5 0 10 10 50 21 70 91 Conserve MORM 4 10 5 5 10 10 50 24 70 94 Conserve MORU 4 10 5 0 10 10 50 19 70 89 Conserve PENL 6 10 5 5 10 10 50 26 70 96 Conserve PENM 6 10 5 5 10 10 50 26 70 96 Conserve PENU 2 10 5 0 2 2 0 17 4 21 No action POOL 10 10 5 5 6 10 50 30 66 96 Conserve POOM 2 0 2 0 6 6 50 4 62 66 Restore POOU 10 10 5 5 6 6 0 30 12 42 No action SOUL 2 0 2 5 6 0 0 9 6 15 No action SOUM 2 10 5 0 2 0 0 17 2 19 No action SOUU 2 10 5 0 2 2 0 17 4 21 No action Key >80 Conserve, 50-80 Restore, <50 No action
161 Figure 4-1. Hierarchy of information of eco logical information (Modified by permission from Innis, S. A., Naiman, R. J. & Ell iott, S. R. 2000. Indicators and assessment methods fo r measuring the ecological integrity of semi-aquatic terrestrial environments. Figure 1 pg 116. Hydrobiologia 422/423
162 No Are native riparian trees present? What is level of site edaphic modification? Is there dredging at the site? Is there evidence of fire? Sorghum Acroceru s Saccharum Vegetation Group Conserve/ Referencesite No action Restore Flemingia Axonopus Bambusa Justicia MoraBactris EschweileraJusticia Yes No Yes Yes No Overgrown beds/furrows/roads/buildings .No active maintenance. Furrows/beds/dirt roads/active site maintenance Paved/concrete areas Trails/ none Figure 4-2. Site management strategies based on taxonomic and classification data
163 Is the indicator a significant determinant of riparian vegetation groups in Trinidad? Can the indicator discriminate between conservation, restoration and "no ac tion sites" in the same manner as detailed classification and taxonomic anal y ses? Does measuring the indicator require extensive time, training, equipment, calculations or software? Choose new variable to assess Is indicator discriminating power duplicated by another more user friendly indicator? Select an indicator used in riparian indices in the literature Physical integrity indicator Anthropogenic/site defensibility Biological integrity indicator Reject indicator Include indicator in index No Yes Yes No No Yes Yes No Figure 4-3Indicator selection process
164 CHAPTER 5 CONCLUSIONS Research Synthesis This study exam ined the structure, composition and determinants of riparian vegetation in Trinidad to provide a baselin e for conservation and restorat ion of the islands riparian ecosystems. A list of 57 native riparian species was identified out of 426 morphoptyes collected. Only 57 plants were classified as ri parian, as the other plan ts were indicative of agriculture and development, rather than ripari an conditions. Weeds and exotic species were excluded from the list, although the exotic species Bambusa vulgaris (Bamboo) had the highest importance value of all the tree species collected and Coffea sp. (Coffee), another exotic had the highest percentage coverage in the ground flora. Overall, 49 exotic species were identified. The list of riparian plants included common forest trees like Carapa guianensis which appear to be facultative species, tolerant of riparian zone conditions. The study showcased a high level of human-i nduced modification of riparian zones and riparian vegetation. Out of 36 sites studied, only nine were classified as forest (FO). Fifteen sites were characterized as secondary vegetation (SV), four as grassland (GR), seven as agriculture (AG) and one as developed (DE). SV sites cons isted largely of abandone d agricultural estates. Apart from land use, riparian zone modificati on also occurred through channel dredging and fires. The influence of land use and exotic s was evident in the ve getation groups found, in which sites clustered into distinct FO, AG and SV groups. Ther e were also a weedy species group, a grass dominated group and one group dominated by Bamboo. Geomorphology separated the FO group into Northern Range and S outhern Plain riparian fo rest. A final, fire influenced group was also found. Significant determ inants of the riparian groups delineated included canopy closure, degree of upland a nd riparian zone edaphic modification,
165 geomorphology, fire, channel modification, distance from paved roads, land ownership, pollution and form factor. While highlighting the modification and degradat ion of riparian zones in Trinidad, this study can also be used as a conservation and re storation guide. The FO sites in this study are representative of natural riparian conditions and can be used as reference and conservation sites, as can the SV sites, especially those in advanced stages of forest rege neration. AG and GR sites were identified as potential rest oration sites, once the natural hydrological regime was intact. Developed sites and fire prone areas were not recommended fo r conservation or restoration owing to persistent human activity. The above management recommendations we re based on the detailed, taxonomic and environmental analyses carried out in this st udy. This study also developed a rapid assessment index, to quickly delineate site management strategi es. Indicators included disturbance, fire and the presence/absence of specific exotics like B. vulgaris and Sorghum sp. An FO site with no exotics and no weeds received a higher index score than a DE site with exotics. High scoring sites were recommended for conservation. Over all, an active riparian width of 30 m was identified. It is recommended that where possibl e, this should be the minimum riparian buffer width for Trinidad. Riparian Research Needs This study provided baseline data on riparian plants in Trinid ad. Tobago was not surveyed due to tim e and budget constraints, but this research gap needs to be filled to improve the knowledge base for riparian management of th e entire country. Also, while Trinidad is a continental island with two large flat plains, To bago is a steep, volcanic island (Water Resources Agency 2001) and a better riparian m odel for other Caribbean islands.
166 The reference sites identified in this study can provide the species template for ecological integrity restoration. However, if the restoration focus is wate r quality, the emphasis may be on plants, which provide effective sediment retent ion and nutrient absorption. This in turn would require experimental work to identify specific plan ts for use. There is already some anecdotal information available to build on. For exam ple, Quesnel & Farrell (2000) suggest that Senna sp. may be good nutrient absorbers. In the interest of ecological integrity, experimental work may also be needed to ensure that the plants selected for nutrient and pollutant absorption, are still capable of providing an adequate food sour ce for terrestrial and aquatic wildlife. Riparian Management in Trinidad Riparian m anagement options in Trinidad incl ude conservation, restoration of sites or else no action because of irreversible land modification or persistent human activity. Sites identified for conservation are high ecological integrity s ites, which are generally capable of supporting ecosystem functions (Karr & Dudley 1981). Low integrity sites can be restored especially if the hydrological regime is intact or if the land use is agriculture and grassland instead of more permanent development. The current paradigm for restoration is hol istic ecosystem restoration. This entails an emphasis on species diversity and heterogeneity in an attempt to en sure ecological resilience (Stanford et al. 1996). Although this is desirable, in Trinidad it may be necessary to focus on specific needs like water quality protection and emphasize plants that effectively uptak e nutrients and pollutants. However, ecological integrity s hould not be overlooked and one po ssibility is restoration for water quality in heavily polluted areas and rest oration for ecological integrity elsewhere. Given the prevalence of exotics in riparian area s, their eradication has to be factored into any restoration scheme in Trinidad. This may not be an easy process as exotics like Bamboo are aggressive colonizers (McClure 1993) and also serve specific purposes, for example, riverbank
167 stabilization (Forestry Divisi on pers comm.). Bamboo removal could be carried out in high priority restoration areas where riverbank st abilization is not as great a priority. Riparian restoration often re quires reestablishing flooding regi mes (Bunn et al. 1998). This may not be possible in Trinidad due to development close to riverbanks and also because of the overwhelming negative public perception of floodi ng. Public awareness programs may help in this regard, but it may be more practical to emph asize conservation in remo te areas with intact flooding regimes or restoration in remote aband oned agricultural areas. Acceptance and support of restoration schemes may be enhanced if historical or cu ltural links to the rivers are emphasized (Higgs 2005). In Trin idad, for example, restoration practitioners could enlist the support of Hindus and Spiritual Baptists who use riparian areas for religious ceremonies. Ameliorative activities in developed areas could include establishing set back levees, which may allow some flooding but protect houses and flood intolerant agriculture beyond the levees. River Management in Trinidad Riparian zone and river m anagement is an im portant issue in Trinid ad, given that 77% of the islands water supply comes fr om surface water sources and also because of the poor quality and quantity of water from these sources (Water Resources Agency 2001). Pollutants like solid waste, sediments, industrial discharges, heavy metals and agricultural chemicals are found in Trinidads rivers. Water shortages occur due to seasonality, exacerbated by unaccounted for water losses in the distribution system (Water Resources Agency 2001). River management is also important as Trinidads aquatic biodive rsity has been identified as a priority for conservation at the regional scale (Olson et al. 1998). This project complements the riverine rese arch program of the Department of Life Sciences, University of the West Indies (UWI), Trinidad. The department has generated faunal and environmental data for rivers in Trinidad. These data in have been used to design a protocol
168 to monitor anthropogenic impacts on the island s rivers for the Environmental Management Authority (Maharaj & Alkins-Koo 2007). The protocol scores sites based on macroinvertebrate taxa supported by physico-chemical data from each site. Land use data are also included in the protocol as are riparian metric s such as percentage vegetation cover in th e riparian zone and vegetation type whether trees, Bamboo, shrubs and grasses (Maharaj & Alkins-Koo 2007). Future revisions of the protocol can perhaps incl ude metrics from the riparian index from this study, for example, presence/absence of exotics like Sorghum sp. as negative indicators of riverine health.
169 APPENDIX A LIST OF SPECIES FOUND IN RIPARIAN ZONES IN TRINIDAD Family Revised name Plant Identification Common name in Trinidad Acanthaceae Acanthaceae Acanthaceae Blechum pyramidatum (Lam.) Urb. Acanthaceae Bravaisia integerrima (Spreng.) Standl. Jiggerwood/White Mangue Acanthaceae Justicia comata (L.) Lam. Acanthaceae Justicia pectoralis Jacq. Acanthaceae Justicia secunda Vahl Acanthaceae Pachystachys spicata (Ruiz & Pav.) Wassh. Pachystachys coccinea (Aubl.) Nees Black stick Acanthaceae Ruellia tuberosa L. Minnie Root Acanthaceae Lepidagathis alopecuroide a (Vhal) R. Br.ex Griseb. Teliostachya alopecuroidea (Vahl) Nees Amaranthaceae Alternanthera tenella Colla Amaranthaceae Amaranthus dubius Mart. ex Thell. Amaryllidaceae Hymenocallis tubiflora Salisb. Onion lilly Anacardiaceae Anacardium occidentale L. Cashew Anacardiaceae Mangifera indica L. Mango Anacardiaceae Spondias mombin L. Hogplum Annonaceae Annona muricata L. Soursop Annonaceae Annona squamosa L. Sugar apple Annonaceae R ollinia exsucca (DC. ex Dunal) A. DC. Apiaceae Eryngium foetidum L. Shadowbenny Apocynaceae Marsdenia macrophylla (Humb. & Bonpl. ex Schult.) E. Fourn. Apocynaceae P restonia quinquangularis (Jacq.) Spreng Apocynaceae Tabernaemontana undulata Vahl Araceae Dieffenbachia seguine (Jacq.) Schott Dumb cane Araceae Monstera obliqua Miq. Araceae Monstera sp. Araceae Philodendron acutatum Schott Araceae Philodendron krugii Engl.
170 Family Revised name Plant Identification Common name in Trinidad Araceae P hilodendron lingulatum (L.) K. Koch Araceae Philodendron sp. Araceae Spathiphyllum cannifolium Schott. Maraval lilly Araceae Xanthosoma ?undipes Araceae Colocasia esculenta (L.) Schott Dasheen Araliaceae Dendropanax arboreus (L.) Decne. & Planch. Araliaceae Schefflera morototoni (Aubl.) Maguire, Steyerm. & Frodin Jereton Arecaceae Attalea maripa (Aubl.) Mart. Cocorite Arecaceae Bactris major Jacq. Gru-Gru Arecaceae Cocos nucifera L. Coconut Arecaceae Desmoncus orthacanthos Mart Wait a while Arecaceae Desmoncus polyacanthos Mart. Wait a while Arecaceae Desmoncus sp. Arecaceae Euterpe oleracea Mart. Arecaceae Euterpe precatoria Mart. Arecaceae Manicaria saccifera Gaertn. Arecaceae Roystonea oleracea (Jacq.) O.F. Cook Royal palm Arecaceae Sabal mauritiiformis (H. Karst.) Griseb. & H. Wendl. Carat palm Asteraceae Ageratum conyzoides L. Asteraceae Bidens alba (L.) DC. Railway daisy Asteraceae Eupatorium iresinoides Kunth Condylidium iresinoides (Kunth) R.M.King & H.Rob Asteraceae Conyza apurensis Kunth Conyza laevigata (Rich.) Pruski Asteraceae Eclipta alba (L.) Hassk. Eclipta prostrata (L.) L. Asteraceae Chromolaena odorata (L.) R.M.King & H.Rob Eupatorium odoratum L. Christmas bush Asteraceae Mikania ?scabra
171 Family Revised name Plant Identification Common name in Trinidad Asteraceae Mikania hookeriana var. p latyphylla (DC.) B.L. Rob. Asteraceae Mikania micrantha Kunth Asteraceae Mikania sp.1 Asteraceae Mikania vitifolia DC. Asteraceae Neurolaena lobata (L.) Cass. Asteraceae Parthenium hysterophorus L. Whitehead Asteraceae Rolandra fruticosa (L.) Kuntze Asteraceae Struchium sparganophorum (L.) Kuntze Asteraceae Tridax procumbens L. Asteraceae Cyanthillium cinereum (L.) H.Rob. Vernonia cinerea (L.) Less. Asteraceae Sphagneticola trilobata (L.) Pruski Wedelia trilobata (L.) Hitchc. Asteraceae Tilesia baccata (L.) Pruski Wulffia baccata (L.) Kuntze Bignoniaceae Bignoniaceae Bignoniaceae Bignoniaceae 1 Bignoniaceae Bignoniaceae 2 Bignoniaceae Bignoniaceae 3 Bignoniaceae Bignoniaceae 4 Bignoniaceae Crescentia cujete L. Calabash Bignoniaceae Macfadyena unguis-cati (L.) A.H. Gentry Cats claw Bignoniaceae P hryganocydia corymbosa (Vent.) Bureau ex K. Schum. Bignoniaceae Pithecoctenium crucigerum (L.) A.H. Gentry Pithecoctenium echinatum (Jacq.) Baill. Monkey hair brush Blechnaceae Blechnum occidentale L. Bombaceae Ceiba pentandra (L.) Gaertn. Silk Cotton, Kapok Bombaceae Ochroma pyramidale (Cav. ex Lam.) Urb. Balsa, Bois Flot Bombaceae Pachira insignis (Sw.) Sw. ex Savigny Wild chataigne Boraginaceae Cordia alliodora (Ruiz & Pav.) OkenCypre Boraginaceae Cordia bicolor A. DC. Boraginaceae Cordia collococca L. Manjack. Boraginaceae Cordia curassavica (Jacq.) Roem. & Schult. Black sage
172 Family Revised name Plant Identification Common name in Trinidad Boraginaceae Heliotropium angiospermum Murray Eyebright/Eyewash Boraginaceae Heliotropium indicum L. Boraginaceae Heliotropium procumbens Mill Brassicaceae (Cruciferae) Rorippa officinale R.Br. Watercress Brassicaceae (Cruciferae) Rorippa indica (L.) Hiern R orippa sinapis (Burm. f.) Ohwi & H. Hara Burseraceae Bursera simaruba (L.) Sarg. Naked Indian Burseraceae Protium guianense (Aubl.) Marchand Incense Campanulaceae Centropogon cornutus (L.) Druce Deermeat Campanulaceae Hippobroma longiflora (L.) G. Don Star of Bethlehem Campanulaceae Sphenoclea zeylanica Gaertn Capparaceae Capparis f rondosa Jacq. Capparis baducca L. Capparaceae Cleome gynandra L. Capparaceae Cleome rutidosperma DC. Capparaceae Cleome spinosa Jacq. Capparaceae Crateva tapia L. Toke Capparaceae Morisonia americana L. Caricaceae Carica papaya L. Paw-paw Cecropiaceae Cecropia peltata L. Bois canot Celestraceae Celestraceae 1 Celestraceae Celestraceae 2 Chrysobalanacea e Hirtella racemosa Lam. Chrysobalanacea e Hirtella triandra Sw. Clusiaceae Calophyllum lucidum Benth. Galba Clusiaceae Mammea americana L. Mamme sepo Clusiaceae Garcinia madruno (Kunth) Hammel Rheedia acuminata (Ruiz & Pav.) Planch. & Triana Wild primose Clusiaceae Vismia cayennensis (Jacq.) Pers. Clusiaceae Vismia laxiflora Reichardt Combretaceae Buchenavia tetraphylla (Aubl.) R.A. Howard Yellow Olivier Combretaceae Combretum fruticosum (Loefl.) Stuntz Combretaceae Terminalia amazonia (J.F. Gmel.) Exell Olivier Combretaceae Terminalia catappa L. Indian Almond
173 Family Revised name Plant Identification Common name in Trinidad Combretaceae Terminalia dichotoma G. Mey. Water Olivier Commelinaceae Commelina diffusa Burm. f. Commelinaceae Commelina erecta L. Commelinaceae Commelina sp. Commelinaceae Gibasis geniculata (Jacq.) Rohweder Commelinaceae Tripogandra serrulata (Vahl) Handlos Connaraceae Rourea surinamensis Miq. Convolvulaceae Convolvulaceae Convolvulaceae Convolvulaceae? Convolvulaceae Ipomea sp. Convolvulaceae Iseia luxurians (Moric.) O'Donell Convolvulaceae Merremia umbellata (L.) Hallier f. Costaceae Costus ?scaber Costaceae Costus scaber Ruiz & Pav. Costaceae Costus sp. Cucurbitaceae Cucurbitaceae Cyatheaceae Cnemidaria ?spectabilis Tree fern Cyatheaceae Cyathea sp.1 Cyclanthaceae Asplundia rigida (Aubl.) Harling Cyclanthaceae Cyclanthus bipartitus Poit Cyperaceae Abildgaardia ovata ? Cyperaceae Cyperaceae Cyperaceae Cyperus luzulae (L.) Rottb. ex Retz. Cyperaceae Cyperus sp. Cyperaceae Cyperus surinamensis Rottb. Cyperaceae Hypolytrum longifolium (Rich.) Nees Cyperaceae Scleria melaleuca Rchb. ex Schltdl. & Cham. Cyperaceae Scleria sp. Cyperaceae Torulinum odoratum (L.) Dilleniaceae Pinzona coriacaea Mart.& Zucc. Pinzona calineoides Eichler Watervine Dracaenaceae Sansevieria hyacinthoides (L.) Mother in Laws tongue
174 Family Revised name Plant Identification Common name in Trinidad Dryopteridaceae Cyclopeltis semicordata (SW.) J.Sm. Dryopteridaceae Diplazium grandifolium (Sw.) Sw. Dryopteridaceae Polybotrya caudata Kunze Dryopteridaceae Tectaria sp.2 Ebenaceae Diospyros inconstans Jacq. Elaeocarpaceae Muntingia calabura L. Euphorbiaceae Acalypha arvensis Poepp. & Endl. Euphorbiaceae Croton gossypiifolius Vahl Bloodwood Euphorbiaceae Croton lobatus L. Euphorbiaceae Chamaesyce hirta (L.) Millsp Euphorbia hirta L. Euphorbiaceae Chamaesyce hyssopifolia (L.) Smnall Euphorbia hyssopifolia L. Euphorbiaceae Hieronyma alchorneoides Allemao Hieronyma laxiflora (Tul.) Mll. Arg. Tapana Euphorbiaceae Hura crepitans L. Sandbox Euphorbiaceae Sapium glandulosum (L.) Morong Milkwood Gentiaceae Enicostema verticillatum (L.) Engl. ex Gilg Gesneriaceae Chrysothemis pulchella (Donn) Decne. Cocoa Flower Gesneriaceae Drymonia serrulata (Jacq.) Mart. Heliconiaceae Heliconia bihai (L.) L. Baliser Heliconiaceae Heliconia bihai/spatho-circinada Heliconiaceae Heliconia hirsuta L. f. Heliconiaceae Heliconia spatho-circinada Aristeg. Hernandiaceae Hernandia sonora L. Toporite Hymenophyllacea e Trichomanes pinnatum Hedw. Lacistemataceae Lacistema aggregatum (P.J. Bergius) Rusby Lamiaceae (Labiatae) Hyptis atrorubens Poit. Lauraceae Lauraceae 1 Lauraceae Lauraceae 2 Lauraceae Lauraceae 3 Lauraceae Lauraceae 4
175 Family Revised name Plant Identification Common name in Trinidad Lauraceae Nectandra tubacensis (Kunth) Nees Nectandra rectinervia Meisn. Lauraceae Ocotea eggersiana Mez Lauraceae Persea americana Mill. Avocado Lecythidaceae Eschweilera subglandulosa (Steud. ex O. Berg) Miers Leguminosae (Fabaceae) Leguminosae Leguminosae (Fabaceae) Subfamily Caesalpinioideae Brownea coccinea Jacq. subsp. capitella (Jacq.) D.Velasquez & Agostini Brownea latifolia Jacq. Mountain Rose Leguminosae (Fabaceae) Subfamily Caesalpinioideae Cassia reticulata Willd. Senna Leguminosae (Fabaceae) Subfamily Caesalpinioideae Crudia glaberrima (Steud.) J.F. Macbr. Leguminosae (Fabaceae) Subfamily Caesalpinioideae Mora excelsa Benth. Leguminosae (Fabaceae) Subfamily Caesalpinioideae Senna bacillaris (L. f.) H.S. Irwin & Barneby Senna Leguminosae (Fabaceae) Subfamily Caesalpinioideae Senna sp. Leguminosae (Fabaceae) Subfamily Caesalpinioideae Swartzia pinnata (Vahl) Willd. Leguminosae (Fabaceae) Subfamily Caesalpinioideae Swartzia simplex (Sw.) Spreng. Leguminosae (Fabaceae) Subfamily Mimosoideae Abarema jupunba (Willd.) Britton & Killip Puni
176 Family Revised name Plant Identification Common name inTrinidad Leguminosae (Fabaceae) Subfamily Mimosoideae Albizia niopoides (Spruce ex. Benth.) Burkart Albizia caribaea (Urb.) Britton & Rose Tantakayo Leguminosae (Fabaceae) Subfamily Mimosoideae Inga ingoides (Rich.) Willd. Padoux Leguminosae (Fabaceae) Subfamily Mimosoideae Inga laurina (Sw.) Willd. Leguminosae (Fabaceae) Subfamily Mimosoideae Inga sp. Leguminosae (Fabaceae) Subfamily Mimosoideae Inga thibaudiana DC. Leguminosae (Fabaceae) Subfamily Mimosoideae Machaerium robiniifolium (DC.) Vogel Leguminosae (Fabaceae) Subfamily Mimosoideae Machaerium isadelpheum (E.Mey.) Amshoff Machaerium tobagense Urb. Leguminosae (Fabaceae) Subfamily Mimosoideae Mimosa casta L. Leguminosae (Fabaceae) Subfamily Mimosoideae Mimosa pigra L. Leguminosae (Fabaceae) Subfamily Mimosoideae Mimosa pudica L Tee marie Leguminosae (Fabaceae) Subfamily Mimosoideae Pentaclethra macroloba (Willd.) Kuntze Fine leaf
177 Family Revised name Plant Identification Common name in Trinidad Leguminosae (Fabaceae) Subfamily Mimosoideae Zygia latifolia (L.) Fawc. & Rendle Leguminosae (Fabaceae) Subfamily Papilionoideae Alysicarpus vaginalis (L.) DC. Leguminosae (Fabaceae) Subfamily Papilionoideae Andira inermis (W. Wright) Kunth ex DC. Angelin Leguminosae (Fabaceae) Subfamily Papilionoideae Centrosema pubescens Benth. Leguminosae (Fabaceae) Subfamily Papilionoideae Clathrotropis brachypetala (Tul.) Kleinhoonte Mayaro Poui Leguminosae (Fabaceae) Subfamily Papilionoideae Coursetia f erruginea (Kunth) Lavin Coursetia ?arborea Leguminosae (Fabaceae) Subfamily Papilionoideae Desmodium adscendens (Sw.) DC. Leguminosae (Fabaceae) Subfamily Papilionoideae Dioclea hexandra (Roxb.) Mabb. Dioclea reflexa Hook. f. Donkey Eye Leguminosae (Fabaceae) Subfamily Papilionoideae Dipteryx odorata (Aubl.) Willd. Tonka Bean Leguminosae (Fabaceae) Subfamily Papilionoideae Erythrina fusca Lour. Erythrina glauca Willd. Water Immortelle Leguminosae (Fabaceae) Subfamily Papilionoideae Erythrina pallida Britton Immortelle Leguminosae (Fabaceae) Subfamily Papilionoideae Erythrina poeppigiana (Walp.) O.F. Cook Immortelle Immortelle
178 Family Revised name Plant Identification Common name in Trinidad Leguminosae (Fabaceae) Subfamily Papilionoideae Erythrina variegata L Leguminosae (Fabaceae) Subfamily Papilionoideae Flemingia strobilifera (L.) R. Br. Wild Hops Leguminosae (Fabaceae) Subfamily Papilionoideae L onchocarpus heptaphyllus (Poir.) DC. Leguminosae (Fabaceae) Subfamily Papilionoideae L onchocarpus sericeus (Poir.) Kunth ex DC Leguminosae (Fabaceae) Subfamily Papilionoideae Platymiscium trinitatis Benth. Roble Leguminosae (Fabaceae) Subfamily Papilionoideae Pterocarpus officinalis Jacq. Bloodwood Leguminosae (Fabaceae) Subfamily Papilionoideae Pueraria phaseoloides (Roxb.) Benth. Kudzoe Lomariospidaceae Lomariopsis japurensis (Mart.) J.Sm. Malpighiaceae Stigmaphyllon sp. Malvaceae Malachra fasciata Jacq. Malvaceae Pavonia castaneifolia A. St.-Hil. & Naudin Malvaceae Sida acuta Burm f. Malvaceae Sida rhombifolia L. Malvaceae Sida sp. Malvaceae Triumfetta ?althaeoides Malvaceae (Sterculiaceae) Guazuma ulmifolia Lam. Bois L'holme Malvaceae (Sterculiaceae) Sterculia pruriens (Aubl.) K. Schum. Mahoe Malvaceae (Sterculiaceae) Theobroma cacao L. Cocoa Maranthaceae Calathea lutea Schult. Maranthaceae Ischnosiphon arouma (Aubl.) Krn. Tirite
179 Family Revised name Plant Identification Common name in Trinidad Maranthaceae Maranta gibba Sm. Melastomataceae Clidemia ?hirta Melastomataceae Clidemia hirta (L.) D. Don Melastomataceae Clidemia sp 1 Melastomataceae Clidemia sp. 2 Melastomataceae Miconia acinodendron (L.) Sweet Melastomataceae Miconia nervosa (Sm.) Triana Melastomataceae Miconia punctata (Desr.) D. Don ex DC. Melastomataceae Miconia sp. Melastomataceae Miconia sp. 1 Melastomataceae Miconia sp. 2 Melastomataceae Miconia sp. 3 Melastomataceae Mouriri rhizophorifolia (DC.) Triana Monkey bone Melastomataceae Pterolepis glomerata (Rottb.) Miq. Meliaceae Carapa guianensis Aubl. Crappo Meliaceae Cedrela odorata L. Cedar Meliaceae Guarea glabra Vahl Meliaceae Guarea guidonia (L.) Sleumer Meliaceae Swietenia macrophylla King Meliaceae Trichilia pallida Sw. Meliaceae Trichilia pleeana (A. Juss.) C. DC. Moraceae Artocarpus altilis (Parkinson) Fosberg Breadfruit/chataigne Moraceae Artocarpus lakoocha Wall. ex Roxb. Barahar Moraceae Brosimum alicastrum SW. Moussara Moraceae Castilla elastica Sess ex Cerv. Rubber Moraceae Ficus amazonica (Miq.) Miq. Moraceae Ficus broadwayi Urb. Moraceae Ficus maxima Mill. Moraceae Ficus numphaeifolia L. Moraceae Ficus trigonata L. Moraceae Ficus yaponensis Desv Mrytaceae Myrcia splendens (Sw.) DC. Musaceae Musa sp. Banana Myristaceae Virola surinamensis (Rol. ex Rottb.) Warb. Myrsinaceae Stylogyne lateriflora (Sw.) Mez Myrtaceae Eugenia baileyi Britton My rtaceae Eugenia monticola (Sw.) DC Myrtaceae Eugenia procera (Sw.) Poir.
180 Family Revised name Plant Identification Common name in Trinidad Myrtaceae Eugenia sp. 1 Myrtaceae Myrtaceae Myrtaceae Myrtaceae? Myrtaceae Psidium guajava L. Guava Myrtaceae Syzygium cumini (L.) Skeels Gulub Jamoon Myrtaceae Syzygium malaccense (L.) Merr. & L.M. Perry Pomerac Nyctaginaceae Pisonia cuspidata Heimerl Nyctaginaceae Pisonia eggersiana Heimerl Nyctaginaceae Pisonia salicifolia Heimerl Oleaceae Chionanthus compactus Sw. Onagraceae Ludwigia ?decurrens Onagraceae Ludwigia erecta (L.) H. Hara Onagraceae Ludwigia peruviana (L.) H. Hara Onagraceae Ludwigia sp. Onagraceae Ludwigia sp. 1 Onagraceae Ludwigia sp. 2 Oxalidaceae Oxalis frutescens L. Passifloraceae Passiflora serratodigitata L. Phyllanthaceae Phyllanthus urinaria L. Piperaceae Peperomia pellucida (L.) Kunth Piperaceae Piper ?aequale Piperaceae Piper ?hispidum Piperaceae Piper aduncum L. Piperaceae Piper hispidum Sw. Piperaceae Piper marginatum Jacq. Piperaceae Piper sp. Piperaceae Piper sp 1 Piperaceae Piper sp. 2 Piperaceae Piper sp. 3 Piperaceae Piper tuberculatum Jacq. Piperaceae Lepianthes p eltata in synonomy Pothomorphe peltata (L. ) Miq.
181 Family Revised name Plant Identification Common name in Trinidad Poaceae Acroceras zizanioides (Kunth) Dandy Poaceae Axonopus compressus (Sw.) P. Beauv. Poaceae Bambusa vulgaris Schrad. ex J.C. Wendl. Poaceae Chrysopogon zizanioides ? Poaceae Cynodon dactylon (L.) Pers. Poaceae Dichanthium caricosum (L.) A. Camus Poaceae Digitaria ?ciliaris Poaceae Echinochloa colonum (L.) Link Poaceae Eleusine indica (L.) Gaertn. Poaceae Eriochloa punctata (L.) Desv. ex Ham. Poaceae Gynerium sagittatum (Aubl.) P. Beauv. Poaceae Hymenachne amplexicaulis (Rudge) Nees Poaceae Hymenachne sp. Poaceae Imperata brasiliensis Trin. Poaceae Ischaemum timorense Kunth Poaceae Lasiacis ligulata Hitchc. & Chase Poaceae Lasiacis sp. Poaceae Leptochloa ?longa Poaceae Leptochloa sp. Poaceae Leptochloa virgata (L.) P. Beauv. Poaceae Olyra latifolia L. Poaceae Oplismenus hirtellus (L.) P. Beauv. Poaceae Panicum stoloniferum Poir. Panicum ?frondescens Poaceae Panicum maximum Jacq. Guinea grass or bull grass Poaceae Panicum sp. Poaceae Panicum sp.? Poaceae Paspalum fasciculatum Willd. ex Flgg Bull grass Poaceae Paspalum sp. Poaceae Pennisetum ?purpureum Poaceae Pennisetum purpureum Schumach. Elephant grass Poaceae Pennisetum sp. Poaceae Pennisetum sp.? Poaceae Pharus latifolius L.
182 Family Revised name Plant Identification Common name in Trinidad Poaceae Piresia sympodica (Dll) Swallen Poaceae Poaceae Poaceae Poaceae 1 Poaceae Poaceae 2 Poaceae Poaceae 3 Poaceae Poaceae 4 Poaceae Poaceae 5 Poaceae Poaceae 6 Poaceae Saccharum officinarum L. Sugarcane Poaceae Setaria ?barbata Poaceae Setaria sp. Poaceae Sorghum arundinacium/halepense Poaceae Urochloa mutica (Forssk.) T.Q. Nguyen Para grass Polygalaceae Securidaca diversifolia (L.) S.F. Blake Polygonaceae Coccoloba fallax Lindau Polygonaceae Coccoloba sp.1 Polygonaceae Coccoloba venosa L. Portulaceace Portulaca quadrifida L. Pteridaceae Adiantum obliquum Willd. Pteridaceae Adiantum pulverulentum L. Pteridaceae Adiantum sp.3 Pteridaceae Adiantum tetraphyllum Hook. Pteridaceae Pityrogramma calomelanos (L.) Link Quiinaceae Quiina cruegeriana Griseb. Rubiaceae Amaioua corymbosa? Rubiaceae Chimarrhis cymosa Jacq. Bois Riviere Rubiaceae Coffea sp. Coffee Rubiaceae Coussarea paniculata (Vahl) Standl. Rubiaceae Diodea ?ocymifolia Rubiaceae Faramea occidentalis (L.) A. Rich Rubiaceae Genipa americana L Rubiaceae Gonzalagunia hirsuta (Jacq.) Schumann Rubiaceae Gonzalagunia spicata (Lam.) M. Gmez Rubiaceae Isertia parviflora Vahl Rubiaceae Palicourea crocea (Sw.) Roem. & Schult.
183 Family Revised name Plant Identification Common name in Trinidad Rubiaceae Psychotria capitata Ruiz & Pav. Rubiaceae Pschotria bahiensis /cuspidata Psychotria cuspidata Bredem. ex Roem. & Schult. Rubiaceae Psychotria deflexa /patens Psychotria patens Sw. Rubiaceae Psychotria poeppigiana Mll. Arg. Rubiaceae Psychotria sp. Rubiaceae Rudgea hostmanniana Benth. Bois tatoo Rubiaceae Spermacoce latifolia Aubl. Rubiaceae Spermacoce sp. Rutaceae Citrus sp. Citrus Rutaceae Zanthoxylum martinicense (Lam.) DC. Rutaceae Zanhoxylum rhoifolium Lam. Zanthoxylum microcarpum Griseb. Rutaceae Zanthoxylum sp. Salicaceae Casearia ?guianensis Salicaceae Casearia guianensis (Aubl.) Urb. Salicaceae Casearia sylvestris Sw. Salicaceae Ryania speciosa Vahl Salicaceae Xylosoma seemannii? Sapindaceae Cardiospermum microcarpum Kunth Sapindaceae Cupania americana L. Sapindaceae Paullinia cururu L Sapindaceae Paullinia fuscescens Kunth Sapindaceae Paullinia leiocarpa Griseb. Sapindaceae Paullinia pinnata L Sapindaceae Sapindus saponaria L. Soapseed Sapindaceae Serjania paucidentata DC Sapotaceae Chrysophyllum argenteum Jacq. Sapotaceae Chrysophyllum cainito L. Caimate Sapotaceae Manilkara bidentata (A. DC.) A. Chev. Balata Sapotaceae Manilkara zapota (L.) P. Royen Sapodilla
184 Family Revised name Plant Identification Common name in Trinidad Sapotaceae Pouteria coriacea (Pierre) Pierre Pouteria minutiflora (Britton) Sandwith Monkey balata Sapotaceae Pouteria multiflora (A. DC.) Eyma Schizaeaceae Lygodium venustum Sw. Schizaeaceae Lygodium volubile Sw. Schizaeaceae Schizaea elegans (Vahl) Sw. Scrophulariaceae Lindernia crustacea (L.) F. Muell. Selaginellaceae Selaginella hartii Hieron Selaginellaceae Selaginella plana (Desv. ex Poir.) Hieron. Simaroubaceae Simarouba amara Aubl. Smilacaceae Smilax cumanensis Humb. & Bonpl. ex Willd. Solanaceae Acnistus arborescens (L.) Schltdl. Solanaceae Solanaceae Solanaceae Solanum jamaicense Mill. Solanaceae Solanum sp. Tectariaceae Hypoderris brownii J.Sm. Tectariaceae Lastreopsis effusa (Sw.) Tindale var divergens (Willd. Ex Schkuhr) Thelypteridaceae Thelypteris serrata (Cav.) Alston Thelypteridaceae Thelypteris sp. 4 Ulmaceae Trema micranthum (L.) Blume Urticaceae Boehmeria ramiflora Jacq. Urticaceae Phenax sonneratii (Poir.) Wedd. Urticaceae Pilea microphylla (L.) Liebm. Urticaceae Urera baccifera (L.) Gaudich. ex Wedd. Verbenaceae Lantana trifolia L. Verbenaceae Priva lappulacea (L.) Pers. Verbenaceae Stachytarpheta jamaicensis (L.) Vahl Vervine Verbenaceae Tectona grandis L. f. Teak Vitaceae Cissus sp. Vitaceae Cissus verticillata (L.) Nicolson & C.E. Jarvis Snake vine Zingiberaceae Renealmia alpinia (Rottb.) Maas Zingiberaceae Zingiber officinale Roscoe Ginger Nomeclature follows (Adams & Baksh-Comeau Unpublished)
185 APPENDIX B PHOTOGRAPHS OF THE LOWER MIDDLE AND UPPE R REACHES OF EACH RIVER STUDIED B-1 Caura Lower B-2 Caura Lower B-3 Caura Middle B-4 Caura Middle B-5 Caura Upper B-6 Caura Upper
186 B-7 Arouca Lower B-8 Arouca Lower B-9 Arouca Middle B-10 Arouca Middle B-11 Arouca Upper B-12 Arouca Upper
187 B-13 North Oropuche Lower B-14 North Oropuche Lower B-15 North Oropuche Middle B-16 North Oropuche Middle B-17 North Oropuche Upper B-18 North Oropuche Upper
188 B-19 Aripo Lower B-20 Aripo Lower B-21 Aripo Middle B-22 Aripo Middle B-23 Aripo Upper B-24 Aripo Upper
189 B-25 Caparo Lower B-26 Caparo Lower B-27 Caparo Middle B-28 Caparo Middle B-29 Caparo Upper B-30 Caparo Upper
190 B-31 Couva Lower B-32 Couva Lower B-33 Couva Middle B-34 Couva Middle B-35 Couva Upper B-36 Couva Upper
191 B-37 Lebranche Lower B-38 Lebranche Lower B-39 Lebranche Middle B-40 Lebranche Middle B-41 Lebranche Upper B-42 Lebranche Upper
192 B-43 Cumuto Lower B-44 Cumuto Lower B-45 Cumuto Middle B-46 Cumuto Middle B-47 Cumuto Upper B-48 Cumuto Upper
193 B-49 Penal Lower B-50 Penal Lower B-51 Penal Middle B-52 Penal Middle B-53 Penal Upper B-54 Penal Upper
194 B-67 South Oropuche Lower B-68 South Oropuche Lower B-69 South Oropuche Middle B-70 South Oropuche Middle B-71 South Oropuche Upper B-72 South Oropuche Upper
195 B-55 Moruga Lower B-56 Moruga Lower B-57 Moruga Middle B-58 Moruga Middle B-59 Moruga Upper B-60 Moruga Upper
196 B-61 Poole Lower B-62 Poole Lower B-63 Poole Middle B-64 Poole Middle B-65 Poole Upper B-66 Poole Upper
197 APPENDIX C SITE LEVEL ENVIRONMENTAL AND LAND USE DATA Site Braiding Meand -ering Elevation above sea level (m) Dischar ge (m3 s-1) Bankslope Channel width (m) Bankfull width (m) Bankfull length (m) Bankfull depth (m) ARIL Y N 30.48 0.86 -28.679.82 12.61 148.33 1.38 ARIM Y N 76.20 0.17 -30.336.37 9.98 690.00 3.24 ARIU N N 228.60 0.02 -14.005.66 12.13 270.00 0.90 AROL N N 15.24 0.64 -21.005.27 27.56 2535.33 9.53 AROM N N 91.44 0.56 -18.0014.09 20.23 258.67 0.98 AROU N N 228.60 0.17 -31.672.79 11.52 675.00 6.10 CAPL N Y 6.10 0.06 -20.673.00 31.67 1232.67 4.86 CAPM N Y 12.19 0.03 -37.002.05 9.36 393.67 2.78 CAPU N N 12.19 0.04 -32.672.85 11.39 573.00 3.50 CAUL N N 30.48 0.79 -36.6710.41 21.45 1116.67 2.62 CAUM N N 91.44 2.17 -18.0011.63 20.03 719.00 2.63 CAUU N N 152.40 0.39 -24.335.78 10.19 536.00 7.09 COUL N Y 6.10 0.14 -28.675.22 18.63 703.00 3.83 COUM N Y 12.19 0.03 -23.672.83 14.24 674.00 3.49 COUU N Y 21.34 0.03 -40.332.58 11.76 404.00 3.12 CUML N Y 30.48 0.09 -28.332.83 17.53 740.67 3.99 CUMM N N 12.19 0.05 -27.004.07 23.46 1052.67 4.98 CUMU N Y 21.34 0.00 -33.003.98 8.37 433.33 2.43 LEBL N N 3.05 0.07 -35.675.05 16.23 678.00 4.16 LEBM N Y 3.05 0.04 -40.334.87 13.29 973.33 7.06 LEBU N N 12.19 0.00 -36.674.30 5.20 143.33 0.86 MORL N Y 2.30 0.00 -25.332.88 15.63 1241.67 5.72 MORM N N 2.30 0.03 -30.002.47 8.66 316.67 1.91 MORU N N 21.33 0.00 -25.331.91 10.51 609.00 2.78 N ORL Y N 7.62 6.42 -35.0012.72 18.61 743.33 5.17 N ORM Y N 45.72 0.21 -20.0010.58 12.53 375.00 1.80 N ORU N N 152.40 3.23 -50.6724.36 30.47 1256.67 11.29 PENL N Y 16.40 0.00 -30.007.53 10.31 936.00 4.90 PENM N Y 49.21 0.00 -34.334.53 13.17 556.67 3.21 PENU N N 67.26 0.00 -21.334.57 7.83 293.33 0.84 POOL N Y 32.81 0.01 -34.674.01 21.64 748.00 4.73 POOM N Y 49.21 0.00 -18.333.68 28.89 1584.67 5.45 POOU N Y 65.62 0.00 -33.001.79 9.67 462.00 3.03 SOUL N N 8.20 0.68 -25.3312.94 21.41 491.00 3.83 SOUM N N 16.40 0.12 -33.004.03 21.68 603.33 3.95 SOUU N N 32.81 0.07 -15.672.03 17.00 1140.00 2.76 Y= Yes, N= No, L= Lower Reach, M= Middle Reach, U=Upper Reach, ARI=Aripo, ARO=Arouca, CAP=Caparo, CAU=Caura, CUM=Cumuto, COU=Couva, LEB=Lebr anche, MOR=Moruga, NO R=North Oropouche, PEN=Penal, POO=Poole, SO U=South Oropouche, L= Lower Reach, M= Middle Reach, U= Upper Reach. De= Developed, W=Water, SV=Secondary Vegetation, FO=Forest, Ag=Agriculture, GR= Grassland
198 APPENDIX D LAND USE, CANOPY CLOSURE, SLOPE AND CUM ULATIVE ELEVATION FOR EACH 10 X 10 M BLOCK River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope Aripo L 0 m 4.00 GR 0.16 -1.74 0.00 Aripo L 0 m 1.00 GR 0.16 -0.52 3.00 Aripo L 0 m 2.00 GR 0.16 -1.05 3.00 Aripo L 0 m 3.00 GR 0.16 -1.74 4.00 Aripo L 0 m 5.00 GR 0.16 -2.79 6.00 Aripo L 100 m 1.00 GR 96.36 2.59 -15.00 Aripo L 100 m 2.00 GR 0.16 3.98 -8.00 Aripo L 100 m 4.00 GR 0.16 3.98 -5.00 Aripo L 100 m 5.00 GR 16.02 3.81 1.00 Aripo L 100 m 3.00 GR 0.16 3.11 5.00 Aripo L 50 m 1.00 GR 0.16 1.91 -11.00 Aripo L 50 m 4.00 GR 0.16 1.56 -3.00 Aripo L 50 m 2.00 GR 0.16 1.56 2.00 Aripo L 50 m 5.00 GR 92.72 1.04 3.00 Aripo L 50 m 3.00 GR 0.16 1.04 3.00 Aripo M 0 m 1.00 FO 98.44 4.07 -24.00 Aripo M 0 m 2.00 SV 98.70 4.42 -2.00 Aripo M 0 m 4.00 SV 15.76 4.59 -1.00 Aripo M 0 m 5.00 SV 0.16 4.59 0.00 Aripo M 0 m 3.00 SV 98.70 4.42 0.00 Aripo M 100 m 1.00 FO 97.66 2.59 -15.00 Aripo M 100 m 4.00 AG 0.16 2.59 -2.00 Aripo M 100 m 5.00 AG 0.16 2.76 -1.00 Aripo M 100 m 2.00 AG 99.74 2.76 -1.00 Aripo M 100 m 3.00 AG 0.16 2.24 3.00 Aripo M 50 m 1.00 FO 93.50 2.42 -14.00 Aripo M 50 m 2.00 FO 95.58 3.46 -6.00 Aripo M 50 m 3.00 AG 0.16 3.81 -2.00 Aripo M 50 m 4.00 AG 0.16 3.81 0.00 Aripo M 50 m 5.00 AG 0.16 3.81 0.00 Aripo U 0 m 4.00 SV 80.24 6.58 -14.00 Aripo U 0 m 2.00 FO 94.80 2.42 -13.00 Aripo U 0 m 5.00 AG 0.16 8.66 -12.00 Aripo U 0 m 3.00 FO 87.52 4.16 -10.00 Aripo U 0 m 1.00 FO 99.74 0.17 -1.00 Aripo U 100 m 3.00 FO 96.62 11.23 -24.00 Aripo U 100 m 2.00 FO 89.08 7.16 -23.00
199 River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope Aripo U 100 m 1.00 FO 97.92 3.26 -19.00 Aripo U 100 m 5.00 SV 98.70 12.80 -6.00 Aripo U 100 m 4.00 SV 96.36 11.75 -3.00 Aripo U 50 m 5.00 SV 29.54 11.58 -15.00 Aripo U 50 m 1.00 FO 93.50 2.59 -15.00 Aripo U 50 m 4.00 SV 82.58 8.99 -14.00 Aripo U 50 m 3.00 FO 99.22 6.57 -13.00 Aripo U 50 m 2.00 FO 92.98 4.32 -10.00 Arouca L 0 m 1.00 GR 0.16 3.58 -21.00 Arouca L 0 m 2.00 GR 0.16 5.83 -13.00 Arouca L 0 m 5.00 DE 0.16 3.21 -3.67 Arouca L 0 m 4.00 DE 0.16 2.57 -3.67 Arouca L 0 m 3.00 GR 0.16 1.93 23.00 Arouca L 100 m 1.00 GR 0.16 3.09 -18.00 Arouca L 100 m 2.00 GR 0.16 5.68 -15.00 Arouca L 100 m 5.00 W 0.16 4.46 1.00 Arouca L 100 m 3.00 GR 0.16 5.16 3.00 Arouca L 100 m 4.00 DE 0.16 4.63 3.00 Arouca L 50 m 1.00 GR 0.16 4.23 -25.00 Arouca L 50 m 2.00 GR 0.16 6.81 -15.00 Arouca L 50 m 3.00 GR 0.16 7.86 -6.00 Arouca L 50 m 4.00 DE 0.16 4.44 20.00 Arouca L 50 m 5.00 DE 0.16 5.55 Arouca M 0 m 2.00 SV 77.90 10.60 -32.00 Arouca M 0 m 1.00 SV 80.24 5.30 -32.00 Arouca M 0 m 5.00 SV 93.24 24.98 -30.00 Arouca M 0 m 3.00 SV 70.62 15.60 -30.00 Arouca M 0 m 4.00 SV 68.02 19.98 -26.00 Arouca M 100 m 5.00 SV 8.48 17.87 -26.00 Arouca M 100 m 4.00 SV 45.92 13.48 -24.00 Arouca M 100 m 3.00 SV 0.16 9.42 -23.00 Arouca M 100 m 1.00 SV 64.12 3.09 -18.00 Arouca M 100 m 2.00 SV 28.76 5.51 -14.00 Arouca M 50 m 2.00 SV 61.00 6.97 -26.00 Arouca M 50 m 5.00 SV 93.24 19.49 -25.00 Arouca M 50 m 3.00 SV 77.90 11.20 -25.00 Arouca M 50 m 4.00 SV 74.26 15.27 -24.00 Arouca M 50 m 1.00 SV 98.44 2.59 -15.00 Arouca U 0 m 1.00 SV 82.06 1.91 -11.00 Arouca U 0 m 2.00 SV 98.70 3.64 -10.00 Arouca U 0 m 4.00 SV 94.54 4.34 -5.00 Arouca U 0 m 3.00 SV 92.46 3.47 1.00 Arouca U 0 m 5.00 SV 99.22 3.99 2.00 Arouca U 100 m 1.00 SV 50.08 8.39 -57.00
200 River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope Arouca U 100 m 2.00 SV 96.88 12.29 -23.00 Arouca U 100 m 5.00 SV 98.70 16.80 -13.00 Arouca U 100 m 3.00 SV 96.10 14.03 -10.00 Arouca U 100 m 4.00 SV 95.32 14.55 -3.00 Arouca U 50 m 1.00 SV 84.40 5.45 -33.00 Arouca U 50 m 2.00 SV 97.92 7.01 -9.00 Arouca U 50 m 5.00 SV 76.86 7.01 0.00 Arouca U 50 m 3.00 SV 71.92 7.01 0.00 Arouca U 50 m 4.00 SV 31.88 7.01 0.00 Caparo L 0 m 1.00 GR 0.16 3.91 -23.00 Caparo L 0 m 3.00 DE 0.16 3.91 -1.00 Caparo L 0 m 2.00 GR 0.16 3.73 1.00 Caparo L 0 m 4.00 GR 0.16 3.73 1.00 Caparo L 0 m 5.00 GR 0.16 3.38 2.00 Caparo L 100 m 1.00 GR 0.16 3.42 -20.00 Caparo L 100 m 5.00 GR 0.16 0.31 -1.00 Caparo L 100 m 4.00 GR 0.16 0.13 -1.00 Caparo L 100 m 3.00 GR 0.16 -0.04 5.00 Caparo L 100 m 2.00 GR 0.16 0.83 15.00 Caparo L 50 m 1.00 GR 0.16 3.91 -23.00 Caparo L 50 m 3.00 DE 0.16 1.83 -1.00 Caparo L 50 m 5.00 AG 0.16 1.66 0.00 Caparo L 50 m 4.00 AG 0.16 1.66 1.00 Caparo L 50 m 2.00 GR 0.16 1.66 13.00 Caparo M 0 m 1.00 FO 98.18 0.35 -2.00 Caparo M 0 m 2.00 SV 23.04 0.35 0.00 Caparo M 0 m 5.00 GR 0.16 -0.87 0.00 Caparo M 0 m 3.00 SV 84.40 0.00 2.00 Caparo M 0 m 4.00 SV 77.38 -0.87 5.00 Caparo M 100 m 1.00 FO 91.68 1.05 -6.00 Caparo M 100 m 3.00 SV 85.70 0.52 0.00 Caparo M 100 m 4.00 GR 93.50 0.17 2.00 Caparo M 100 m 2.00 SV 85.18 0.52 3.00 Caparo M 100 m 5.00 GR 67.76 -0.35 3.00 Caparo M 50 m 1.00 FO 93.76 1.05 -6.00 Caparo M 50 m 3.00 SV 59.44 1.74 -3.00 Caparo M 50 m 4.00 SV 94.28 1.92 -1.00 Caparo M 50 m 2.00 SV 83.10 1.22 -1.00 Caparo M 50 m 5.00 SV 95.84 1.92 0.00 Caparo U 0 m 1.00 GR 0.16 0.52 -3.00 Caparo U 0 m 5.00 AG 0.16 0.17 -1.00 Caparo U 0 m 3.00 AG 0.16 0.17 0.00 Caparo U 0 m 4.00 AG 0.16 0.00 1.00 Caparo U 0 m 2.00 AG 0.16 0.17 2.00
201 River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope Caparo U 100 m 1.00 GR 37.08 0.87 -5.00 Caparo U 100 m 2.00 AG 0.16 1.05 -1.00 Caparo U 100 m 4.00 AG 0.16 0.87 -1.00 Caparo U 100 m 3.00 AG 0.16 0.70 2.00 Caparo U 100 m 5.00 AG 0.16 0.35 3.00 Caparo U 50 m 1.00 GR 0.16 0.87 -5.00 Caparo U 50 m 2.00 AG 0.16 0.87 0.00 Caparo U 50 m 3.00 AG 0.16 0.87 0.00 Caparo U 50 m 4.00 AG 0.16 0.87 0.00 Caparo U 50 m 5.00 AG 0.16 0.87 0.00 Caura L 0 m 1.00 FO 47.22 7.66 -50.00 Caura L 0 m 2.00 DE 70.88 8.36 -4.00 Caura L 0 m 3.00 DE 0.16 8.36 0.00 Caura L 0 m 4.00 DE 0.16 8.36 0.00 Caura L 0 m 5.00 DE 0.16 8.36 0.00 Caura L 100 m 1.00 FO 0.16 1.74 -10.00 Caura L 100 m 2.00 DE 0.16 1.74 0.00 Caura L 100 m 3.00 DE 0.16 1.74 0.00 Caura L 100 m 4.00 DE 0.16 1.74 0.00 Caura L 100 m 5.00 DE 0.16 1.74 0.00 Caura L 50 m 1.00 FO 98.18 5.88 -36.00 Caura L 50 m 2.00 DE 8.22 5.88 0.00 Caura L 50 m 3.00 DE 0.16 5.88 0.00 Caura L 50 m 4.00 DE 0.16 5.88 0.00 Caura L 50 m 5.00 DE 0.16 5.88 0.00 Caura M 0 m 5.00 FO 98.96 12.40 -29.00 Caura M 0 m 4.00 FO 94.54 7.55 -21.00 Caura M 0 m 1.00 FO 87.26 2.59 -15.00 Caura M 0 m 2.00 FO 98.44 4.67 -12.00 Caura M 0 m 3.00 FO 97.66 3.97 4.00 Caura M 100 m 4.00 FO 98.96 23.51 -40.00 Caura M 100 m 3.00 FO 91.68 17.08 -40.00 Caura M 100 m 2.00 FO 96.62 10.65 -40.00 Caura M 100 m 1.00 FO 98.96 4.23 -25.00 Caura M 100 m 5.00 FO 98.44 26.10 -15.00 Caura M 50 m 4.00 FO 77.90 14.82 -30.00 Caura M 50 m 3.00 FO 97.66 9.82 -30.00 Caura M 50 m 5.00 FO 96.10 18.24 -20.00 Caura M 50 m 1.00 FO 99.74 3.26 -19.00 Caura M 50 m 2.00 FO 98.44 4.82 -9.00 Caura U 0 m 1.00 SV 96.88 1.39 -8.00 Caura U 0 m 4.00 SV 91.68 1.57 -1.00 Caura U 0 m 5.00 SV 82.84 1.57 0.00
202 River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope Caura U 0 m 2.00 SV 95.84 1.39 0.00 Caura U 0 m 3.00 SV 95.58 1.39 0.00 Caura U 100 m 5.00 SV 97.66 18.01 -36.00 Caura U 100 m 4.00 SV 81.54 12.14 -23.00 Caura U 100 m 1.00 SV 95.58 3.75 -22.00 Caura U 100 m 2.00 SV 90.38 6.84 -18.00 Caura U 100 m 3.00 SV 66.20 8.23 -8.00 Caura U 50 m 1.00 GR 89.08 2.08 -12.00 Caura U 50 m 5.00 SV 92.46 4.52 -5.00 Caura U 50 m 3.00 SV 96.88 3.65 -5.00 Caura U 50 m 2.00 SV 98.18 2.78 -4.00 Caura U 50 m 4.00 SV 93.24 3.65 0.00 Couva L 0 m 3.00 GR 87.52 9.53 -24.00 Couva L 0 m 1.00 FO 91.16 4.07 -24.00 Couva L 0 m 2.00 FO 94.54 5.46 -8.00 Couva L 0 m 4.00 GR 92.98 10.40 -5.00 Couva L 0 m 5.00 GR 0.16 10.40 0.00 Couva L 100 m 1.00 FO 96.36 4.23 -25.00 Couva L 100 m 3.00 FO 94.28 6.65 -13.00 Couva L 100 m 5.00 FO 94.02 7.70 -5.00 Couva L 100 m 4.00 FO 94.80 6.82 -1.00 Couva L 100 m 2.00 FO 91.42 4.40 -1.00 Couva L 50 m 1.00 FO 93.50 5.30 -32.00 Couva L 50 m 2.00 GR 95.06 10.45 -31.00 Couva L 50 m 3.00 FO 95.58 13.04 -15.00 Couva L 50 m 4.00 FO 66.46 13.56 -3.00 Couva L 50 m 5.00 GR 0.16 13.56 0.00 Couva M 0 m 4.00 GR 19.92 7.45 -15.00 Couva M 0 m 1.00 SV 94.80 1.74 -10.00 Couva M 0 m 3.00 GR 14.46 4.86 -10.00 Couva M 0 m 2.00 GR 95.32 3.13 -8.00 Couva M 0 m 5.00 DE 0.16 7.45 0.00 Couva M 100 m 5.00 DE 0.16 5.60 -26.00 Couva M 100 m 4.00 SV 96.62 1.22 -5.00 Couva M 100 m 2.00 SV 74.00 0.52 -5.00 Couva M 100 m 3.00 SV 83.36 0.35 1.00 Couva M 100 m 1.00 SV 89.60 -0.35 2.00 Couva M 50 m 3.00 SV 86.74 5.49 -22.00 Couva M 50 m 2.00 SV 90.12 1.74 -8.00 Couva M 50 m 1.00 SV 95.58 0.35 -2.00 Couva M 50 m 4.00 GR 61.52 5.84 -2.00 Couva M 50 m 5.00 DE 0.16 5.84 0.00
203 River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope Couva U 0 m 2.00 SV 90.12 3.96 -18.00 Couva U 0 m 3.00 SV 51.90 4.83 -5.00 Couva U 0 m 1.00 SV 96.36 0.87 -5.00 Couva U 0 m 5.00 SV 96.62 5.01 -1.00 Couva U 0 m 4.00 SV 84.40 4.83 0.00 Couva U 100 m 3.00 SV 22.26 5.44 -25.00 Couva U 100 m 5.00 SV 51.12 9.43 -14.00 Couva U 100 m 4.00 SV 94.02 7.01 -9.00 Couva U 100 m 1.00 SV 97.14 1.22 -7.00 Couva U 100 m 2.00 SV 80.76 1.22 0.00 Couva U 50 m 2.00 SV 92.46 4.60 -23.00 Couva U 50 m 5.00 SV 91.42 7.56 -10.00 Couva U 50 m 3.00 SV 97.14 5.48 -5.00 Couva U 50 m 1.00 SV 96.36 0.70 -4.00 Couva U 50 m 4.00 SV 88.04 5.83 -2.00 Cumuto L 0 m 1.00 SV 95.06 2.25 -13.00 Cumuto L 0 m 4.00 SV 88.04 3.82 -3.00 Cumuto L 0 m 3.00 SV 93.24 3.30 -3.00 Cumuto L 0 m 2.00 SV 85.44 2.77 -3.00 Cumuto L 0 m 5.00 SV 47.48 3.47 2.00 Cumuto L 100 m 1.00 SV 65.68 3.75 -22.00 Cumuto L 100 m 2.00 SV 97.92 4.62 -5.00 Cumuto L 100 m 5.00 SV 40.72 5.32 -4.00 Cumuto L 100 m 3.00 SV 96.62 4.62 0.00 Cumuto L 100 m 4.00 SV 61.00 4.62 0.00 Cumuto L 50 m 4.00 SV 93.24 1.05 -3.00 Cumuto L 50 m 3.00 SV 97.40 0.52 -3.00 Cumuto L 50 m 5.00 SV 95.84 1.05 0.00 Cumuto L 50 m 1.00 SV 97.66 0.00 0.00 Cumuto L 50 m 2.00 SV 97.14 0.00 0.00 Cumuto M 0 m 1.00 GR 0.16 3.26 -19.00 Cumuto M 0 m 4.00 AG 0.16 1.51 2.00 Cumuto M 0 m 2.00 AG 0.16 2.73 3.00 Cumuto M 0 m 5.00 AG 0.16 0.99 3.00 Cumuto M 0 m 3.00 AG 0.16 1.86 5.00 Cumuto M 100 m 1.00 GR 0.16 3.91 -23.00 Cumuto M 100 m 2.00 GR 0.16 4.60 -4.00 Cumuto M 100 m 5.00 AG 0.16 4.43 -1.00 Cumuto M 100 m 3.00 AG 0.16 4.43 1.00 Cumuto M 100 m 4.00 AG 0.16 4.26 1.00 Cumuto M 50 m 1.00 GR 0.16 6.69 -42.00 Cumuto M 50 m 2.00 AG 38.38 6.52 1.00
204 River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope Cumuto M 50 m 3.00 AG 30.58 6.17 2.00 Cumuto M 50 m 4.00 AG 0.16 5.82 2.00 Cumuto M 50 m 5.00 AG 0.16 5.30 3.00 Cumuto U 0 m 1.00 FO 87.52 4.07 -24.00 Cumuto U 0 m 2.00 AG 88.04 6.32 -13.00 Cumuto U 0 m 4.00 AG 0.16 8.06 -5.00 Cumuto U 0 m 3.00 AG 90.64 7.19 -5.00 Cumuto U 0 m 5.00 AG 0.16 8.58 -3.00 Cumuto U 100 m 1.00 FO 92.72 4.23 -25.00 Cumuto U 100 m 2.00 FO 85.18 5.10 -5.00 Cumuto U 100 m 3.00 AG 45.92 5.62 -3.00 Cumuto U 100 m 4.00 AG 1.46 5.62 0.00 Cumuto U 100 m 5.00 AG 0.16 5.10 3.00 Cumuto U 50 m 1.00 FO 98.96 5.00 -30.00 Cumuto U 50 m 3.00 FO 95.58 6.40 -4.00 Cumuto U 50 m 2.00 FO 98.96 5.70 -4.00 Cumuto U 50 m 4.00 AG 88.82 6.92 -3.00 Cumuto U 50 m 5.00 FO 78.42 7.09 -1.00 Lebranche L 0 m 3.00 SV 53.20 6.88 -18.00 Lebranche L 0 m 1.00 GR 34.22 3.09 -18.00 Lebranche L 0 m 5.00 DE 0.16 8.62 -5.00 Lebranche L 0 m 4.00 DE 14.20 7.75 -5.00 Lebranche L 0 m 2.00 SV 69.84 3.79 -4.00 Lebranche L 100 m 1.00 SV 45.66 6.56 -41.00 Lebranche L 100 m 4.00 SV 92.98 8.82 -8.00 Lebranche L 100 m 2.00 SV 91.42 7.95 -8.00 Lebranche L 100 m 5.00 SV 31.10 8.47 2.00 Lebranche L 100 m 3.00 SV 79.20 7.43 3.00 Lebranche L 50 m 1.00 GR 89.60 4.85 -29.00 Lebranche L 50 m 4.00 SV 17.84 8.98 -18.00 Lebranche L 50 m 2.00 SV 98.70 6.41 -9.00 Lebranche L 50 m 5.00 DE 0.16 10.02 -6.00 Lebranche L 50 m 3.00 SV 97.40 5.89 3.00 Lebranche M 0 m 1.00 SV 88.82 3.91 -23.00 Lebranche M 0 m 2.00 GR 93.76 5.30 -8.00 Lebranche M 0 m 3.00 SV 99.22 6.00 -4.00 Lebranche M 0 m 5.00 SV 96.62 5.65 0.00 Lebranche M 0 m 4.00 SV 91.94 5.65 2.00 Lebranche M 100 m 1.00 SV 84.92 5.30 -32.00 Lebranche M 100 m 2.00 SV 96.10 6.69 -8.00 Lebranche M 100 m 5.00 SV 96.62 5.47 0.00 Lebranche M 100 m 3.00 SV 97.14 6.52 1.00
205 River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope Lebranche M 100 m 4.00 SV 98.18 5.47 6.00 Lebranche M 50 m 1.00 SV 97.40 4.23 -25.00 Lebranche M 50 m 4.00 SV 97.14 4.57 -5.00 Lebranche M 50 m 2.00 SV 97.14 4.40 -1.00 Lebranche M 50 m 5.00 SV 93.76 4.40 1.00 Lebranche M 50 m 3.00 SV 84.40 3.70 4.00 Lebranche U 0 m 1.00 SV 96.10 1.91 -11.00 Lebranche U 0 m 5.00 GR 79.46 2.26 -5.00 Lebranche U 0 m 4.00 SV 84.14 1.38 -3.00 Lebranche U 0 m 2.00 SV 95.06 1.56 2.00 Lebranche U 0 m 3.00 SV 90.90 0.86 4.00 Lebranche U 100 m 1.00 SV 97.66 2.59 -15.00 Lebranche U 100 m 3.00 SV 91.42 2.76 -3.00 Lebranche U 100 m 4.00 SV 92.72 2.76 0.00 Lebranche U 100 m 2.00 GR 96.88 2.24 2.00 Lebranche U 100 m 5.00 GR 91.42 2.06 4.00 Lebranche U 50 m 2.00 SV 70.36 0.70 -4.00 Lebranche U 50 m 4.00 SV 4.32 1.22 -3.00 Lebranche U 50 m 5.00 SV 56.84 1.22 0.00 Lebranche U 50 m 3.00 SV 51.90 0.70 0.00 Lebranche U 50 m 1.00 GR 23.04 0.00 0.00 Moruga L 0 m 1.00 FO 71.92 3.91 -23.00 Moruga L 0 m 5.00 FO 98.44 6.52 -10.00 Moruga L 0 m 2.00 FO 78.16 4.78 -5.00 Moruga L 0 m 3.00 FO 99.22 4.95 -1.00 Moruga L 0 m 4.00 FO 97.92 4.78 1.00 Moruga L 100 m 1.00 FO 90.64 5.59 -34.00 Moruga L 100 m 3.00 FO 99.48 14.04 -25.00 Moruga L 100 m 2.00 FO 94.54 9.82 -25.00 Moruga L 100 m 4.00 FO 97.92 16.63 -15.00 Moruga L 100 m 5.00 FO 97.14 11.78 29.00 Moruga L 50 m 1.00 FO 88.82 4.07 -24.00 Moruga L 50 m 2.00 FO 88.56 7.49 -20.00 Moruga L 50 m 4.00 FO 98.18 13.67 -18.00 Moruga L 50 m 3.00 FO 98.96 10.58 -18.00 Moruga L 50 m 5.00 FO 99.48 16.42 -16.00 Moruga M 0 m 1.00 GR 0.16 3.09 -18.00 Moruga M 0 m 2.00 GR 0.16 4.83 -10.00 Moruga M 0 m 3.00 GR 71.40 6.22 -8.00 Moruga M 0 m 4.00 FO 96.88 7.09 -5.00 Moruga M 0 m 5.00 FO 96.62 8.86 Moruga M 100 m 1.00 GR 0.16 3.91 -23.00
206 River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope Moruga M 100 m 5.00 FO 98.44 7.06 -10.25 Moruga M 100 m 2.00 FO 60.48 4.78 -5.00 Moruga M 100 m 3.00 FO 97.66 5.30 -3.00 Moruga M 100 m 4.00 FO 99.22 5.65 -2.00 Moruga M 50 m 1.00 GR 0.16 4.85 -29.00 Moruga M 50 m 2.00 FO 84.66 6.07 -7.00 Moruga M 50 m 3.00 FO 100.00 6.94 -5.00 Moruga M 50 m 4.00 FO 100.00 6.76 1.00 Moruga M 50 m 5.00 FO 100.00 8.45 Moruga U 0 m 3.00 FO 98.18 8.57 -24.00 Moruga U 0 m 2.00 FO 99.22 4.50 -13.00 Moruga U 0 m 1.00 FO 99.22 2.25 -13.00 Moruga U 0 m 4.00 FO 96.62 10.30 -10.00 Moruga U 0 m 5.00 FO 98.18 6.24 24.00 Moruga U 100 m 1.00 GR 87.00 3.91 -23.00 Moruga U 100 m 3.00 FO 98.70 5.47 -7.00 Moruga U 100 m 4.00 FO 98.96 6.52 -6.00 Moruga U 100 m 2.00 FO 99.22 4.26 -2.00 Moruga U 100 m 5.00 FO 99.74 5.65 5.00 Moruga U 50 m 3.00 FO 93.76 7.31 -24.00 Moruga U 50 m 1.00 FO 98.96 3.42 -20.00 Moruga U 50 m 2.00 FO 95.06 3.25 1.00 Moruga U 50 m 4.00 FO 98.70 6.96 2.00 Moruga U 50 m 5.00 FO 91.68 3.06 23.00 N orth Oropuche L 0 m 1.00 FO 97.14 2.59 -15.00 N orth Oropuche L 0 m 3.00 FO 97.66 5.20 -10.00 N orth Oropuche L 0 m 2.00 FO 98.44 3.46 -5.00 N orth Oropuche L 0 m 4.00 SV 92.72 5.02 1.00 N orth Oropuche L 0 m 5.00 SV 0.16 4.85 1.00 N orth Oropuche L 100 m 1.00 SV 98.44 2.08 -12.00 N orth Oropuche L 100 m 2.00 SV 91.16 3.82 -10.00 N orth Oropuche L 100 m 5.00 AG 0.16 5.03 -7.00 N orth Oropuche L 100 m 3.00 SV 33.96 3.82 0.00 N orth Oropuche L 100 m 4.00 AG 50.08 3.82 0.00 N orth Oropuche L 50 m 1.00 SV 87.78 3.58 -21.00 N orth Oropuche L 50 m 3.00 SV 85.70 7.05 -14.00 N orth Oropuche L 50 m 2.00 SV 90.90 4.63 -6.00 N orth Oropuche L 50 m 4.00 SV 98.18 7.22 -1.00 N orth Oropuche L 50 m 5.00 SV 91.16 7.05 1.00 N orth Oropuche M 0 m 1.00 SV 93.50 3.91 -23.00 N orth Oropuche M 0 m 5.00 SV 43.84 10.12 -16.00 N orth Oropuche M 0 m 2.00 GR 78.94 6.50 -15.00
207 River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope N orth Oropuche M 0 m 4.00 GR 18.88 7.37 -6.00 N orth Oropuche M 0 m 3.00 SV 84.40 6.32 1.00 N orth Oropuche M 100 m 2.00 SV 61.00 3.28 -16.00 N orth Oropuche M 100 m 5.00 GR 0.16 6.06 -11.00 N orth Oropuche M 100 m 4.00 GR 89.34 4.15 -7.00 N orth Oropuche M 100 m 1.00 GR 8.74 0.52 -3.00 N orth Oropuche M 100 m 3.00 GR 90.90 2.93 2.00 N orth Oropuche M 50 m 5.00 GR 88.30 6.56 -30.00 N orth Oropuche M 50 m 1.00 GR 43.58 1.91 -11.00 N orth Oropuche M 50 m 4.00 GR 33.44 1.56 -5.00 N orth Oropuche M 50 m 2.00 GR 28.24 1.56 2.00 N orth Oropuche M 50 m 3.00 GR 0.16 0.69 5.00 N orth Oropuche U 0 m 1.00 FO 78.94 7.07 -45.00 N orth Oropuche U 0 m 5.00 FO 98.96 7.76 -10.00 N orth Oropuche U 0 m 4.00 FO 97.66 6.03 -3.00 N orth Oropuche U 0 m 3.00 FO 97.14 5.50 4.00 N orth Oropuche U 0 m 2.00 FO 92.46 6.20 5.00 N orth Oropuche U 100 m 1.00 FO 66.72 6.43 -40.00 N orth Oropuche U 100 m 4.00 FO 96.10 11.40 -20.00 N orth Oropuche U 100 m 3.00 FO 97.92 7.98 -14.00 N orth Oropuche U 100 m 5.00 FO 100.00 13.65 -13.00 N orth Oropuche U 100 m 2.00 FO 98.96 5.56 5.00 N orth Oropuche U 50 m 1.00 FO 53.98 7.66 -50.00 N orth Oropuche U 50 m 5.00 SV 98.96 9.52 -19.00 N orth Oropuche U 50 m 3.00 FO 95.84 7.14 -5.00 N orth Oropuche U 50 m 4.00 FO 95.58 6.27 5.00 N orth Oropuche U 50 m 2.00 FO 98.96 6.27 8.00 Penal L 0 m 1.00 FO 85.44 5.74 -35.00 Penal L 0 m 2.00 FO 69.06 9.80 -24.00 Penal L 0 m 3.00 FO 86.48 13.71 -23.00 Penal L 0 m 4.00 FO 88.04 15.45 -10.00 Penal L 0 m 5.00 FO 83.62 16.67 -7.00 Penal L 100 m 1.00 FO 85.70 5.30 -32.00 Penal L 100 m 2.00 FO 87.78 7.89 -15.00 Penal L 100 m 4.00 FO 89.08 11.36 -12.00 Penal L 100 m 5.00 FO 37.34 12.92 -9.00 Penal L 100 m 3.00 FO 62.30 9.28 -8.00 Penal L 50 m 4.00 FO 84.66 14.79 -35.00 Penal L 50 m 1.00 FO 89.34 5.00 -30.00 Penal L 50 m 5.00 FO 89.08 19.64 -29.00 Penal L 50 m 3.00 FO 78.68 9.05 -25.00 Penal L 50 m 2.00 FO 69.32 4.83 1.00
208 River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope Penal M 0 m 1.00 FO 95.58 4.69 -28.00 Penal M 0 m 2.00 FO 64.12 7.11 -14.00 Penal M 0 m 5.00 FO 97.14 9.72 -10.00 Penal M 0 m 3.00 FO 59.44 7.99 -5.00 Penal M 0 m 4.00 FO 90.64 7.99 0.00 Penal M 100 m 1.00 FO 96.62 3.91 -23.00 Penal M 100 m 4.00 FO 91.94 4.95 -4.00 Penal M 100 m 3.00 FO 93.76 4.26 -1.00 Penal M 100 m 2.00 FO 97.40 4.08 -1.00 Penal M 100 m 5.00 FO 86.22 4.26 4.00 Penal M 50 m 1.00 FO 90.64 4.23 -25.00 Penal M 50 m 5.00 FO 78.16 8.01 -18.00 Penal M 50 m 4.00 FO 14.72 4.92 -5.00 Penal M 50 m 2.00 FO 97.92 4.23 0.00 Penal M 50 m 3.00 FO 75.56 4.05 1.00 Penal U 0 m 2.00 AG 12.90 5.84 -19.00 Penal U 0 m 1.00 AG 69.32 2.59 -15.00 Penal U 0 m 5.00 AG 4.84 9.50 -8.00 Penal U 0 m 3.00 AG 39.16 7.24 -8.00 Penal U 0 m 4.00 AG 5.10 8.11 -5.00 Penal U 100 m 1.00 AG 8.22 3.91 -23.00 Penal U 100 m 4.00 AG 20.96 10.12 -19.00 Penal U 100 m 5.00 AG 4.06 12.87 -16.00 Penal U 100 m 3.00 AG 19.14 6.86 -10.00 Penal U 100 m 2.00 AG 18.88 5.13 -7.00 Penal U 50 m 3.00 AG 6.66 6.05 -15.00 Penal U 50 m 1.00 AG 64.90 2.59 -15.00 Penal U 50 m 4.00 AG 5.10 8.30 -13.00 Penal U 50 m 5.00 AG 5.10 9.86 -9.00 Penal U 50 m 2.00 AG 14.98 3.46 -5.00 Poole L 0 m 1.00 SV 91.42 3.75 -22.00 Poole L 0 m 5.00 SV 96.62 8.60 -10.00 Poole L 0 m 2.00 SV 95.84 5.31 -9.00 Poole L 0 m 4.00 SV 78.94 6.88 -8.00 Poole L 0 m 3.00 SV 75.56 5.48 -1.00 Poole L 100 m 2.00 FO 94.80 5.80 -33.00 Poole L 100 m 4.00 FO 92.20 13.93 -25.00 Poole L 100 m 3.00 FO 97.40 9.70 -23.00 Poole L 100 m 5.00 FO 95.06 15.85 -20.50 Poole L 100 m 1.00 FO 92.72 0.35 -2.00 Poole L 50 m 3.00 SV 97.66 11.72 -36.00 Poole L 50 m 4.00 SV 90.64 16.57 -29.00
209 River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope Poole L 50 m 5.00 SV 96.62 18.64 -21.88 Poole L 50 m 2.00 SV 87.00 5.84 -19.00 Poole L 50 m 1.00 SV 93.50 2.59 -15.00 Poole M 0 m 1.00 SV 0.16 3.09 -18.00 Poole M 0 m 2.00 SV 83.10 5.85 -16.00 Poole M 0 m 4.00 SV 96.88 5.15 1.00 Poole M 0 m 5.00 SV 72.70 4.80 2.00 Poole M 0 m 3.00 SV 95.84 5.32 3.00 Poole M 100 m 1.00 SV 78.94 4.69 -28.00 Poole M 100 m 2.00 SV 83.62 7.11 -14.00 Poole M 100 m 5.00 SV 93.50 6.94 0.00 Poole M 100 m 4.00 SV 90.12 6.94 0.00 Poole M 100 m 3.00 SV 93.76 6.94 1.00 Poole M 50 m 1.00 AG 91.94 3.26 -19.00 Poole M 50 m 2.00 SV 96.10 5.33 -12.00 Poole M 50 m 3.00 SV 22.00 5.86 -3.00 Poole M 50 m 4.00 SV 97.66 5.68 1.00 Poole M 50 m 5.00 SV 100.00 5.51 1.00 Poole U 0 m 1.00 SV 98.44 1.39 -8.00 Poole U 0 m 2.00 SV 97.66 1.92 -3.00 Poole U 0 m 3.00 SV 95.32 2.09 -1.00 Poole U 0 m 5.00 SV 96.62 1.57 0.00 Poole U 0 m 4.00 SV 95.84 1.57 3.00 Poole U 100 m 1.00 SV 96.88 1.56 -9.00 Poole U 100 m 5.00 SV 94.80 1.39 -3.00 Poole U 100 m 3.00 SV 97.66 1.39 0.00 Poole U 100 m 2.00 SV 97.66 1.39 1.00 Poole U 100 m 4.00 SV 93.24 0.87 3.00 Poole U 50 m 4.00 SV 94.28 4.69 -11.00 Poole U 50 m 2.00 SV 93.50 2.78 -8.00 Poole U 50 m 1.00 SV 94.28 1.39 -8.00 Poole U 50 m 5.00 SV 91.42 5.21 -3.00 Poole U 50 m 3.00 SV 90.12 2.78 0.00 South Oropouche L 0 m 1.00 SV 94.28 0.87 -5.00 South Oropouche L 0 m 2.00 SV 71.66 1.39 -3.00 South Oropouche L 0 m 3.00 AG 0.16 1.92 -3.00 South Oropouche L 0 m 5.00 SV 0.16 1.57 1.00 South Oropouche L 0 m 4.00 AG 0.16 1.74 1.00 South Oropouche L 100 m 1.00 SV 79.20 3.91 -23.00 South Oropouche L 100 m 3.00 SV 0.16 4.26 -2.00 South Oropouche L 100 m 4.00 AG 0.16 4.43 -1.00 South Oropouche L 100 m 2.00 SV 66.98 3.91 0.00
210 River Reach Transect Block Land use Canopy closure (%) Cumulative elevation (m) Slope South Oropouche L 100 m 5.00 AG 0.16 3.91 3.00 South Oropouche L 50 m 1.00 SV 0.16 2.76 -16.00 South Oropouche L 50 m 2.00 SV 94.80 4.49 -10.00 South Oropouche L 50 m 3.00 SV 0.16 4.49 0.00 South Oropouche L 50 m 4.00 AG 0.16 4.49 0.00 South Oropouche L 50 m 5.00 AG 0.16 4.32 1.00 South Oropouche M 0 m 1.00 FO 97.92 3.91 -23.00 South Oropouche M 0 m 3.00 AG 0.16 4.95 -3.00 South Oropouche M 0 m 2.00 AG 0.16 4.43 -3.00 South Oropouche M 0 m 5.00 AG 0.16 5.13 -1.00 South Oropouche M 0 m 4.00 AG 0.16 4.95 0.00 South Oropouche M 100 m 1.00 GR 51.64 3.91 -23.00 South Oropouche M 100 m 2.00 AG 0.16 4.08 -1.00 South Oropouche M 100 m 3.00 AG 0.16 4.08 0.00 South Oropouche M 100 m 4.00 AG 0.16 3.56 3.00 South Oropouche M 100 m 5.00 AG 0.16 3.04 3.00 South Oropouche M 50 m 1.00 GR 49.04 3.91 -23.00 South Oropouche M 50 m 3.00 AG 0.16 4.78 -4.00 South Oropouche M 50 m 5.00 AG 0.16 5.13 -1.00 South Oropouche M 50 m 4.00 AG 0.16 4.95 -1.00 South Oropouche M 50 m 2.00 AG 0.16 4.08 -1.00 South Oropouche U 0 m 3.00 AG 0.16 2.79 -9.00 South Oropouche U 0 m 2.00 AG 0.16 1.22 -4.00 South Oropouche U 0 m 1.00 GR 30.06 0.52 -3.00 South Oropouche U 0 m 4.00 AG 0.16 3.31 -3.00 South Oropouche U 0 m 5.00 AG 0.16 2.44 5.00 South Oropouche U 100 m 1.00 GR 24.86 1.91 -11.00 South Oropouche U 100 m 2.00 AG 23.56 2.43 -3.00 South Oropouche U 100 m 4.00 AG 0.16 2.43 -1.00 South Oropouche U 100 m 5.00 AG 0.16 2.43 0.00 South Oropouche U 100 m 3.00 AG 0.16 2.26 1.00 South Oropouche U 50 m 1.00 GR 0.16 3.91 -23.00 South Oropouche U 50 m 2.00 AG 0.16 7.00 -18.00 South Oropouche U 50 m 5.00 AG 0.16 9.09 -6.00 South Oropouche U 50 m 4.00 AG 0.16 8.04 -3.00 South Oropouche U 50 m 3.00 AG 0.16 7.52 -3.00 De= Developed, W=Water, SV=Secondary Vege tation, FO=Forest, Ag=Agriculture, GR= Grassland. L= Lower Reach, M=Middle Reach, U=Upper Reach
211 APPENDIX E PHYSICAL AND CHEMICAL SOIL PARA ME TERS FOR EACH 10 X 10 M BLOCK
212River Reach Block pH (30 cm) N (30 cm) (g kg-1) P(30 cm) (mg kg-1) K(30 cm) (c mol kg-1) Ca(30 cm) (c mol kg-1) Mg(30 cm) (c mol kg-1) EC (30 cm) (mS cm-1) OC (30 cm) (g kg1) pH (60 cm) N (60 cm) (g kg-1) P(60 cm)(mg kg-1) K(60 cm) (c mol kg-1) Ca(60 cm) (c mol kg-1) Mg(60 cm) (c mol kg-1) EC (60 cm) (mS 1) OC (60 cm) (g kg1) % clay % sand % silt % gravel Aripo L1 6.37 0.90 16.00 0.01 2.53 0.23 0.205.006.151.2015.000.01 2.2600.170.135.004.0078.5917.410.00 Aripo L2 6.01 1.00 14.00 0.01 2.11 0.24 0.467.005.220.6010.000.01 1.1900.210.182.008.9861.5529.470.00 Aripo L3 6.55 8.00 13.00 0.01 3.17 0.28 0.218.006.3510.0018.000.01 3.3700.220.1410.007.5666.6425.800.00 Aripo L4 7.10 19.00 31.00 0.02 6.52 0.45 0.5119.006.4912.0015.000.01 2.7100.190.2112.0011.5937.6550.760.00 Aripo L5 6.77 1.40 17.00 0.01 5.83 0.28 0.2816.005.771.4011.000.01 3.4150.270.2017.0012.903 649.940.00 Aripo M1 8.14 2.00 4.00 0.01 14.11 0.04 0.160.708.011.003.000.01 12.6700.060.120.001.6250.030.9047.45 Aripo M2 7.20 9.00 10.00 0.01 7.54 0.24 0.2212.007.002.008.000.01 6.8000.110.2813.004.1175.0913.177.62 Aripo M3 5.78 1.70 24.00 0.01 4.34 0.32 0.1320.005.771.706.000.01 1.1350.040.0914.005.8949.7744.340.00 Aripo M4 5.26 1.40 57.00 0.04 4.13 0.30 0.2019.005.222.1010.000.02 4.2800.220.077.005.8962.0032.110.00 Aripo M5 5.55 1.80 92.00 0.03 5.70 0.21 0.1820.005.321.8078.000.02 4.3350.190.1716.0014.1963.2422.570.00 Aripo U1 7.90 2.20 2.00 0.02 23.28 1.03 0.6942.007.861.602.000.01 25.9750.970.3126.002.2945.4411.1441.13 Aripo U2 7.85 2.80 3.00 0.02 26.01 1.33 0.7948.007.932.502.000.02 26.5051.240.6642.0010.6960.3428.980.00 Aripo U3 7.90 2.70 15.00 0.01 25.97 1.13 0.6353.007.882.803.000.01 26.5800.930.6948.003.5369.0427.430.00 Aripo U4 7.74 3.90 5.00 0.02 25.58 1.34 1.0789.007.972.103.000.02 26.6850.850.6640.004.4075.2520.350.00 Aripo U5 7.91 2.30 1.00 0.01 25.80 0.83 0.6230.005.650.502.000.01 25.3350.790.4320.004.8224.5912.2258.37 Arouca L1 7.27 0.80 13.00 0.01 6.31 0.37 0.199.007.491.0020.000.01 4.0600.380.207.006.4174.6918.900.00 Arouca L2 7.55 1.00 17.00 0.01 5.57 0.43 0.226.007.461.0013.000.01 5.3900.300.258.004.4077.3218.280.00 Arouca L3 6.81 1.40 24.00 0.02 7.16 0.88 0.2715.007.251.8013.000.02 5.6550.830.2519.0016.0834.7949.140.00 Arouca L4 6.91 2.60 26.00 0.12 10.26 1.37 0.7025.006.942.2026.000.13 9.3701.050.7227.0013.5136.9349.570.00 Arouca L5 xx xx xx xx xx xx xx xx xx xx xx xx xx xx xxxx 10.1055.9333.970.00 Arouca M1 7.39 0.30 5.00 0.01 2.09 0.33 0.114.007.371.704.000.01 3.5800.530.0810.002.3558.993.9234.74 Arouca M2 5.66 0.80 2.00 0.02 4.44 1.55 0.1431.005.701.302.000.01 3.8450.450.0816.002.9636.167.7353.16 Arouca M3 5.41 n 2.00 0.02 5.14 0.53 0.1126.005.572.603.000.01 2.9100.210.0510.0010.7756.0733.160.00 Arouca M4 5.42 1.80 3.00 0.05 6.03 1.15 0.1638.005.752.102.000.03 4.3400.680.1119.0016.8643.8639.280.00 Arouca M5 5.80 1.50 1.00 0.02 6.27 1.16 0.1640.005.76n 2.000.02 5.6350.510.1530.0012.8048.0039.200.00 Arouca U1 5.14 2.60 5.00 0.05 1.66 1.23 0.2218.004.751.405.000.05 0.8801.120.1412.005.8959.9634.150.00 Arouca U2 4.76 1.80 6.00 0.04 0.48 1.78 0.2140.004.581.307.000.02 0.3051.150.1112.0014.3243.6542.030.00 Arouca U3 4.26 2.30 13.00 0.02 0.88 1.13 0.0640.004.290.905.000.02 0.2200.510.0613.0020.1128.0551.840.00
213River Reach Block pH (30 cm) N (30 cm) (g kg-1) P(30 cm) (mg kg-1) K(30 cm) (c mol kg-1) Ca(30 cm) (c mol kg-1) Mg(30 cm) (c mol kg-1) EC (30 cm) (mS cm-1) OC (30 cm) (g kg1) pH (60 cm) N (60 cm) (g kg-1) P(60 cm)(mg kg-1) K(60 cm) (c mol kg-1) Ca(60 cm) (c mol kg-1) Mg(60 cm) (c mol kg-1) EC (60 cm) (mS 1) OC (60 cm) (g kg1) % clay % sand % silt % gravel Arouca U4 4.52 1.90 3.00 0.02 1.43 1.38 0.1629.004.411.302.000.02 0.1400.760.088.0016.7531.9051.350.00 Arouca U5 4.15 0.90 5.00 0.04 0.32 0.91 0.1826.004.220.802.000.01 0.0400.240.0614.0019.4825.8554.670.00 Caparo M1 5.39 15.10 20.00 0.04 11.40 3.35 1.0943.004.2717.3012.000.04 7.9052.330.5441.0033.6812.9553.370.00 Caparo M2 5.98 n 27.00 0.05 16.32 4.68 0.3844.005.8715.7024.000.03 11.5453.760.1522.0021.2739.3239.420.00 Caparo M3 5.20 23.80 17.00 0.03 12.92 4.13 0.3139.005.5920.4020.000.03 10.7403.490.1720.0018.7049.8131.490.00 Caparo M4 5.39 12.30 17.00 0.03 13.43 3.76 0.1939.005.6213.7017.000.02 10.8853.230.1022.0043.7210.0746.210.00 Caparo M5 5.77 9.10 19.00 0.02 13.74 4.31 0.2135.005.3618.9017.000.02 5.3354.760.1417.0048.235.5546.220.00 Caparo U1 6.96 16.20 27.00 0.02 16.73 2.85 0.236.006.945.7028.000.01 15.4002.760.168.0023.5333.9742.510.00 Caparo U2 6.98 15.60 35.00 0.03 23.11 4.74 0.3221.006.4219.2029.000.03 21.9553.500.2427.0023.7118.2858.010.00 Caparo U3 6.35 15.40 27.00 0.03 19.20 3.82 0.1725.006.4315.6019.000.03 11.7602.350.1214.0032.5916.2351.180.00 Caparo U4 5.88 18.00 21.00 0.03 13.04 3.02 0.1731.006.0713.9017.000.03 10.8102.740.1215.0030.4816.5652.960.00 Caparo U5 6.04 15.90 15.00 0.05 11.25 2.04 0.2036.00xx xx xx xx xx xx xxxx 28.3719.6751.960.00 Caparo L1 7.83 1.70 17.00 0.01 6.77 7.79 0.713.008.101.4016.000.02 6.7608.340.784.0029.6119.9350.470.00 Caparo L2 5.40 0.70 15.00 0.07 7.83 5.08 0.4219.005.950.707.000.05 6.2755.720.3912.0040.033.1056.870.00 Caparo L3 7.07 1.90 19.00 0.05 7.22 4.66 2.0217.006.211.8018.000.03 4.9302.961.133.0026.8511.4261.730.00 Caparo L4 4.72 2.00 10.00 0.09 6.86 5.65 0.2717.004.831.9011.000.05 6.0105.130.1616.0030.3211.4258.270.00 Caparo L5 4.86 1.00 6.00 0.06 6.62 5.11 0.1316.004.931.606.000.04 5.7955.390.1515.0027.8815.3156.810.00 Caura L1 6.69 1.70 11.00 0.01 13.02 1.11 0.2624.007.941.608.000.01 5.6101.090.5318.005.7428.8124.9440.51 Caura L2 6.53 0.50 10.00 0.01 4.65 0.47 0.0913.006.441.807.000.01 5.9500.810.1218.008.7748.4342.800.00 Caura L3 6.97 0.50 9.00 0.02 2.14 0.37 0.189.006.300.705.000.01 2.8200.250.075.005.5470.8623.600.00 Caura L4 7.14 0.20 68.00 0.03 9.31 1.38 0.2031.007.281.3070.000.02 14.8400.850.2227.006.1268.7525.130.00 Caura L5 6.89 2.30 73.00 0.12 17.50 3.65 0.4543.007.201.3077.000.05 13.5202.580.2726.009.3649.1541.490.00 Caura M1 6.96 1.20 7.00 0.01 5.70 0.80 0.1911.006.960.708.000.01 1.5350.430.188.002.9169.868.0719.16 Caura M2 4.76 2.10 3.00 0.03 1.53 0.65 0.1151.004.602.402.000.02 1.0950.560.0834.003.6869.0427.270.00 Caura M3 6.92 1.50 3.00 0.02 0.45 0.56 0.0929.004.510.702.000.01 0.0500.320.0411.005.3161.5833.110.00 Caura M4 4.79 2.10 7.00 0.02 1.82 0.77 0.1945.004.681.904.000.02 1.4800.580.1132.006.1254.9438.940.00 Caura M5 4.65 6.40 8.00 0.03 2.24 0.91 0.1747.004.632.103.000.02 1.8150.730.1424.007.7460.2731.990.00 Caura U1 5.72 0.90 9.00 0.01 1.44 1.32 0.1712.005.721.4011.000.01 0.8101.300.105.001.3030.384.3463.98 Caura U2 5.70 1.30 10.00 0.01 4.14 1.70 0.3032.005.612.708.000.01 3.3601.550.3326.003.6883.1213.200.00 Caura U3 5.37 0.90 10.00 0.01 2.60 1.38 0.2227.005.601.608.000.01 2.8101.260.1420.009.5762.2128.220.00 Caura U4 4.85 1.20 5.00 0.02 1.72 1.46 0.3128.004.721.602.000.01 0.5301.000.1114.004.2547.5748.180.00 Caura U5 4.60 1.50 4.00 0.02 1.18 1.38 0.2624.004.331.404.000.02 0.7951.010.1916.007.5641.4051.040.00 Couva L1 7.18 18.00 25.00 0.03 17.67 5.22 0.6118.008.117.0038.000.02 20.8904.780.367.0023.6941.1935.120.00 Couva L2 7.62 1.80 58.00 0.03 22.63 4.48 0.7430.007.702.4072.000.03 22.6103.950.4628.0018.7658.1923.050.00
214River Reach Block pH (30 cm) N (30 cm) (g kg-1) P(30 cm) (mg kg-1) K(30 cm) (c mol kg-1) Ca(30 cm) (c mol kg-1) Mg(30 cm) (c mol kg-1) EC (30 cm) (mS cm-1) OC (30 cm) (g kg1) pH (60 cm) N (60 cm) (g kg-1) P(60 cm)(mg kg-1) K(60 cm) (c mol kg-1) Ca(60 cm) (c mol kg-1) Mg(60 cm) (c mol kg-1) EC (60 cm) (mS 1) OC (60 cm) (g kg1) % clay % sand % silt % gravel Couva L3 5.68 36.00 7.00 0.05 9.62 5.23 0.3136.005.7623.006.000.03 7.5654.730.1723.0017.4934.1748.340.00 Couva L4 5.70 36.00 3.00 0.05 8.14 4.10 0.1636.005.6219.003.000.02 4.9303.570.0819.0020.9524.8454.210.00 Couva L5 5.11 22.00 3.00 0.04 7.16 3.58 0.1022.005.3914.003.000.03 5.8953.920.0814.0030.3121.5448.150.00 Couva M1 7.76 1.40 43.00 0.03 19.12 4.17 0.9313.007.991.8040.000.02 18.3004.380.8115.0021.9135.2242.880.00 Couva M2 6.39 2.20 20.00 0.05 10.34 3.91 0.2712.005.772.9017.000.03 9.3354.850.1827.0017.4942.6739.840.00 Couva M3 7.11 2.20 151.00 0.04 10.81 3.95 0.1523.005.771.3020.000.02 9.5454.050.1712.0010.3648.7040.940.00 Couva M4 5.82 3.60 12.00 0.08 8.43 2.65 0.3142.005.462.108.000.05 6.9452.480.3122.0018.8931.5749.540.00 Couva M5 5.12 2.30 12.00 0.07 10.49 3.12 0.4748.004.840.707.000.04 4.4552.460.1923.0020.7634.4044.840.00 Couva U1 6.78 1.60 5.00 0.01 5.13 0.75 0.2018.007.271.606.000.01 5.7750.760.2719.0010.7763.0326.210.00 Couva U2 6.33 1.60 6.00 0.01 4.67 0.82 0.1720.006.471.606.000.01 4.9650.770.1419.008.1949.7123.4018.70 Couva U3 6.21 1.60 20.00 0.01 4.84 0.85 0.2325.006.171.605.000.01 3.8000.860.2215.002.0640.5926.1031.25 Couva U4 6.23 1.60 6.00 0.01 4.35 0.84 0.3324.006.431.605.000.01 4.6950.830.2218.008.1469.3322.530.00 Couva U5 6.63 1.60 6.00 0.01 5.38 1.07 0.2023.006.551.603.000.01 4.3101.040.1816.009.5259.0931.390.00 Cumuto L1 4.84 8.40 10.00 0.02 4.55 0.94 0.119.004.355.807.000.02 3.0500.560.1110.0018.8554.2226.940.00 Cumuto L2 4.59 11.50 5.00 0.02 2.64 0.51 0.1621.004.778.604.000.02 2.1600.420.056.0015.3543.7540.900.00 Cumuto L3 4.27 8.10 9.00 0.02 2.28 0.54 0.1115.004.403.405.000.01 2.5050.430.052.0017.6436.1946.170.00 Cumuto L4 5.59 10.10 7.00 0.02 2.83 0.50 0.1516.005.587.205.000.02 2.6100.410.105.0018.9329.9151.160.00 Cumuto L5 5.58 8.40 5.00 0.02 4.27 0.65 0.1314.005.581.604.000.02 0.5150.240.085.0018.3527.1254.530.00 Cumuto M1 4.56 9.00 8.00 0.01 0.37 1.67 0.080.604.251.105.000.01 0.4351.180.060.7018.2662.8318.910.00 Cumuto M2 5.65 2.30 7.00 0.04 8.11 2.33 0.2532.005.671.907.000.02 7.2002.230.1529.009.7647.2842.950.00 Cumuto M3 5.44 1.60 8.00 0.07 7.86 2.58 0.2537.004.901.805.000.04 6.1852.480.1623.0015.6728.7955.540.00 Cumuto M4 5.35 2.30 4.00 0.06 5.84 5.51 0.2336.005.051.604.000.03 4.1505.020.0613.0029.6219.8450.540.00 Cumuto M5 5.82 1.50 4.00 0.04 5.37 3.85 0.0922.005.451.703.000.02 4.8453.760.0814.0016.4641.6241.920.00 Cumuto U1 7.87 2.30 8.00 0.02 6.45 2.09 0.2816.005.291.105.000.01 5.7301.310.155.0022.9628.7848.260.00 Cumuto U2 6.85 3.40 16.00 0.02 14.75 2.16 0.4546.006.692.209.000.02 11.6352.050.2123.0026.6340.3233.050.00 Cumuto U3 5.97 xx 7.00 0.02 10.51 2.53 0.2841.006.49xx 11.000.01 9.9652.010.3016.0011.1630.3358.510.00 Cumuto U4 5.68 xx 6.00 0.02 8.37 2.73 0.2842.005.69xx 4.000.02 7.1902.430.1323.0013.0027.6159.390.00 Cumuto U5 5.67 xx 6.00 0.02 8.15 2.61 0.2936.005.55xx 6.000.02 8.1350.430.1012.0018.7129.0752.210.00 Lebranche L1 5.94 3.10 5.00 0.02 5.47 0.70 0.7815.006.381.504.000.01 4.3600.610.620.0018.6760.7820.560.00 Lebranche L2 5.84 1.80 5.00 0.02 4.63 0.70 0.3317.005.740.903.000.01 3.6750.620.141.0020.6450.9028.470.00 Lebranche L3 5.62 3.10 4.00 0.04 8.44 0.98 0.2731.005.632.203.000.03 8.5550.900.1426.0022.3936.8040.810.00 Lebranche L4 5.61 2.70 5.00 0.03 8.01 0.88 0.2331.005.612.504.000.02 7.9100.830.1313.0025.7619.5154.720.00 Lebranche L5 7.97 2.00 5.00 0.10 25.41 0.44 0.3135.007.882.905.000.11 25.3200.440.3525.0015.8355.4828.690.00 Lebranche M1 5.24 1.80 1.00 0.03 3.66 0.79 0.1223.005.041.401.000.02 3.0200.790.0712.0024.3142.0333.660.00
215River Reach Block pH (30 cm) N (30 cm) (g kg-1) P(30 cm) (mg kg-1) K(30 cm) (c mol kg-1) Ca(30 cm) (c mol kg-1) Mg(30 cm) (c mol kg-1) EC (30 cm) (mS cm-1) OC (30 cm) (g kg1) pH (60 cm) N (60 cm) (g kg-1) P(60 cm)(mg kg-1) K(60 cm) (c mol kg-1) Ca(60 cm) (c mol kg-1) Mg(60 cm) (c mol kg-1) EC (60 cm) (mS 1) OC (60 cm) (g kg1) % clay % sand % silt % gravel Lebranche M2 6.17 1.90 2.00 0.03 10.46 2.01 0.2439.006.601.702.000.02 6.4801.620.1217.0017.0840.1842.740.00 Lebranche M3 5.47 2.40 2.00 0.03 8.30 2.80 0.2635.005.121.301.000.02 5.1901.990.1324.0025.6923.2051.110.00 Lebranche M4 4.88 1.80 2.00 0.02 5.63 1.71 0.1220.004.931.401.000.02 5.4401.230.0920.0030.1915.5154.310.00 Lebranche M5 4.96 2.30 1.00 0.02 5.08 1.96 0.1426.005.031.601.000.02 4.5201.690.0815.0029.4817.8752.650.00 Lebranche U1 4.70 2.60 5.00 0.05 2.96 1.43 0.3322.004.722.103.000.05 2.5101.180.3426.0035.2523.4141.350.00 Lebranche U2 4.54 5.10 3.00 0.03 1.43 1.31 0.1120.004.602.402.000.03 1.2001.310.1118.0038.2215.8245.960.00 Lebranche U3 5.13 5.10 4.00 0.04 4.69 2.28 0.2135.004.932.403.000.03 2.8901.280.2328.0029.7522.7947.460.00 Lebranche U4 5.86 4.50 6.00 0.09 12.26 3.43 0.5572.005.553.105.000.07 5.8902.530.3040.0029.7530.5739.680.00 Lebranche U5 4.76 4.90 7.00 0.12 5.13 3.64 0.2755.004.632.803.000.14 4.2353.800.2735.0038.4325.2536.330.00 Moruga L1 6.70 1.20 13.00 0.03 4.34 1.23 0.4515.006.551.0010.000.03 3.6100.980.3813.0024.1831.3644.460.00 Moruga L2 5.36 1.20 10.00 0.03 4.21 0.83 0.2425.005.551.609.000.03 3.0901.040.1917.0011.5957.6830.730.00 Moruga L3 4.80 2.10 4.00 0.05 3.07 0.88 0.2231.004.671.902.000.04 2.4251.050.1824.0018.1235.3646.510.00 Moruga L4 4.90 1.70 1.00 0.08 3.70 1.33 0.2826.004.291.303.000.05 1.4700.970.1216.0027.9021.0951.010.00 Moruga L5 4.87 1.10 2.00 0.05 3.86 1.40 0.1115.004.340.901.000.04 0.7150.970.1010.0028.3832.6538.970.00 Moruga M1 5.36 1.10 8.00 0.04 7.36 3.52 0.3829.005.301.206.000.02 6.6553.300.2929.0019.0039.6841.320.00 Moruga M2 5.28 2.60 10.00 0.07 8.24 0.41 0.2317.005.131.408.000.02 4.1650.170.1618.0016.6840.8642.460.00 Moruga M3 5.41 1.10 5.00 0.05 5.04 0.08 0.2027.005.330.104.000.01 2.8750.030.089.0021.5630.7147.730.00 Moruga M4 4.67 2.00 3.00 0.14 5.00 0.13 0.1111.004.681.403.000.05 2.3300.130.067.0016.8935.3034.7613.05 Moruga M5 5.20 0.80 4.00 0.21 4.28 0.10 0.1117.005.012.204.000.02 2.1950.100.0810.0016.7745.9431.176.11 Moruga U1 5.16 1.80 18.00 0.06 5.88 4.03 0.6731.004.551.6018.000.05 4.7203.520.7923.0013.8148.0038.190.00 Moruga U2 5.36 2.00 20.00 0.04 6.97 5.42 0.3836.005.491.4015.000.03 5.6954.840.2327.0021.7724.0554.180.00 Moruga U3 5.37 2.60 11.00 0.04 6.83 5.99 0.3641.005.222.206.000.03 5.7655.270.2532.0024.9926.0748.940.00 Moruga U4 4.66 1.70 4.00 0.03 1.65 2.57 0.2426.004.901.404.000.02 0.7952.260.1417.005.8849.5118.5026.10 Moruga U5 7.69 2.20 4.00 0.04 3.11 2.44 0.6543.005.122.702.000.02 2.4151.940.1528.005.1759.2323.3712.23 North Oropouche L1 4.09 xx 6.00 0.01 1.72 0.25 0.10xx 4.12xx 5.000.01 0.5150.060.11xx 6.5883.979.460.00 North Oropouche L2 4.97 xx 2.00 0.01 1.10 0.34 0.06xx 5.06xx 3.000.01 0.5250.200.05xx 10.5971.2818.130.00 North Oropouche L3 4.32 xx 3.00 0.01 0.87 0.26 0.08xx 4.24xx 2.000.01 0.6900.180.04xx 16.6127.8255.570.00 North Oropouche L4 3.94 xx 3.00 0.01 0.78 0.22 0.10xx 3.94xx 4.000.01 0.5300.230.07xx 20.3012.5467.160.00 North Oropouche L5 3.81 xx 4.00 0.01 3.07 0.59 0.10xx 3.96xx 8.000.01 0.5950.230.07xx 18.2810.9970.720.00 North Oropouche M1 8.19 2.00 5.00 0.02 7.99 0.35 0.2739.007.231.006.000.01 6.2650.260.360.002.2249.281.8346.66
216River Reach Block pH (30 cm) N (30 cm) (g kg-1) P(30 cm) (mg kg-1) K(30 cm) (c mol kg-1) Ca(30 cm) (c mol kg-1) Mg(30 cm) (c mol kg-1) EC (30 cm) (mS cm-1) OC (30 cm) (g kg1) pH (60 cm) N (60 cm) (g kg-1) P(60 cm)(mg kg-1) K(60 cm) (c mol kg-1) Ca(60 cm) (c mol kg-1) Mg(60 cm) (c mol kg-1) EC (60 cm) (mS 1) OC (60 cm) (g kg1) % clay % sand % silt % gravel North Oropouche M2 8.09 1.70 12.00 0.01 11.01 0.33 0.190.008.090.505.000.01 10.0350.360.221.001.5350.281.4546.74 North Oropouche M3 7.73 1.70 10.00 0.01 23.46 0.48 0.4540.007.821.609.000.02 21.4000.420.3924.003.0871.2425.680.00 North Oropouche M4 6.55 1.30 8.00 0.01 7.29 0.28 0.2931.006.511.409.000.01 5.1000.240.3526.003.7066.7329.580.00 North Oropouche M5 6.81 2.30 20.00 0.03 17.24 3.35 0.4647.007.500.407.000.01 11.6851.600.3827.006.9859.7133.310.00 North Oropouche U1 7.31 1.20 55.00 0.02 15.22 1.03 0.8022.007.780.8019.000.02 10.9150.690.634.005.8951.2042.910.00 North Oropouche U2 4.84 1.30 8.00 0.02 2.73 0.40 0.4827.004.262.203.000.01 0.6950.250.2418.009.8060.3429.860.00 North Oropouche U3 4.09 0.80 6.00 0.03 1.67 0.52 0.4541.004.122.503.000.01 1.1300.580.1722.0020.7649.7729.470.00 North Oropouche U4 4.25 1.30 3.00 0.02 1.18 0.30 0.1334.004.221.402.000.01 0.6800.460.0126.0017.8153.0329.160.00 North Oropouche U5 4.23 1.60 3.00 0.01 2.34 0.46 0.2527.004.08n 3.000.01 1.1800.400.1332.0035.7735.4828.750.00 Penal L1 6.00 2.30 15.00 0.06 11.21 2.40 1.1143.004.892.0015.000.06 10.1552.450.7330.0047.0813.2339.690.00 Penal L2 5.96 2.40 4.00 0.04 8.55 2.08 0.1725.005.711.202.000.04 6.1002.410.0912.0024.8437.7837.380.00 Penal L3 6.09 2.80 8.00 0.05 8.72 1.63 0.2845.006.082.205.000.04 7.1501.920.1828.0021.8930.0848.030.00 Penal L4 6.98 2.50 3.00 0.07 13.12 1.61 0.4039.007.703.005.000.05 13.3851.950.5546.0038.0421.1040.860.00 Penal L5 5.92 2.80 6.00 0.06 8.72 3.07 0.2941.005.712.004.000.05 6.4153.040.2023.0021.5738.4539.980.00 Penal M1 7.87 1.80 22.00 0.03 24.99 2.99 0.8118.007.322.0013.000.05 14.2101.680.7013.0045.0725.6329.300.00 Penal M2 5.60 2.70 6.00 0.08 7.25 2.26 0.2629.004.992.303.000.06 5.6802.260.1623.0020.6939.7039.610.00 Penal M3 6.41 2.90 7.00 0.08 11.12 1.84 0.3140.006.302.906.000.07 10.3302.290.2938.0016.4846.8236.690.00 Penal M4 5.46 3.10 5.00 0.05 7.92 2.65 0.2135.005.462.704.000.05 7.8302.670.2333.0023.2935.3541.360.00 Penal M5 5.99 2.30 4.00 0.08 8.92 3.64 0.3433.005.912.304.000.08 8.3304.130.3220.0027.7436.7535.510.00 Penal U1 6.05 1.50 2.00 0.05 10.94 3.00 0.5614.006.021.202.000.04 10.7303.610.3616.0054.6613.5231.820.00 Penal U2 6.48 2.30 2.00 0.08 9.42 0.97 0.3448.005.801.902.000.06 7.7701.050.2627.0029.0644.8726.060.00 Penal U3 4.82 2.30 2.00 0.09 2.97 1.32 0.2718.004.552.303.000.08 2.9251.580.2116.0053.4023.6023.000.00 Penal U4 4.95 2.80 4.00 0.11 4.79 1.75 0.2434.004.802.003.000.10 3.5401.780.1814.0051.7621.1527.090.00 Penal U5 5.10 2.90 4.00 0.11 3.71 1.40 0.4142.004.521.803.000.09 3.1001.670.1917.0041.1137.2021.690.00 Poole L1 4.80 11.40 8.00 0.03 5.07 2.55 0.1712.004.808.506.000.03 4.7802.500.1815.0033.8615.4350.710.00 Poole L2 4.52 14.00 5.00 0.02 3.18 1.26 0.1213.004.587.905.000.02 1.1700.920.098.0015.6251.5032.880.00 Poole L3 4.35 10.20 5.00 0.02 2.33 2.02 0.1419.004.458.405.000.02 1.4101.030.098.0016.2449.9133.850.00
217River Reach Block pH (30 cm) N (30 cm) (g kg-1) P(30 cm) (mg kg-1) K(30 cm) (c mol kg-1) Ca(30 cm) (c mol kg-1) Mg(30 cm) (c mol kg-1) EC (30 cm) (mS cm-1) OC (30 cm) (g kg1) pH (60 cm) N (60 cm) (g kg-1) P(60 cm)(mg kg-1) K(60 cm) (c mol kg-1) Ca(60 cm) (c mol kg-1) Mg(60 cm) (c mol kg-1) EC (60 cm) (mS 1) OC (60 cm) (g kg1) % clay % sand % silt % gravel Poole L4 4.46 5.40 4.00 0.02 0.71 1.23 0.0815.004.762.905.000.01 0.3551.230.069.0020.3450.5929.060.00 Poole L5 4.35 8.60 5.00 0.04 1.32 1.91 0.2039.004.395.605.000.02 0.4451.590.0911.0016.8643.8639.280.00 Poole M1 5.88 11.70 10.00 0.05 8.64 4.99 0.176.005.173.608.000.04 8.1455.130.1310.0027.0335.7737.200.00 Poole M2 5.88 11.90 17.00 0.02 11.64 3.00 0.1120.005.8812.1014.000.02 7.0251.880.1016.0021.6739.0639.270.00 Poole M3 4.75 16.90 11.00 0.03 8.74 3.16 0.1020.004.681.609.000.03 7.2602.940.0612.0021.5221.1057.370.00 Poole M4 6.88 25.80 11.00 0.04 21.95 2.02 0.5436.006.216.3011.000.03 16.3001.540.2017.0015.1439.9444.920.00 Poole M5 4.88 14.80 11.00 0.03 6.65 2.54 0.1219.004.7812.7010.000.03 5.6352.630.1216.0021.6218.2860.100.00 Poole U1 5.08 2.30 7.00 0.02 5.63 3.49 0.3618.005.691.304.000.02 4.7652.790.369.0023.1239.3037.580.00 Poole U2 4.39 2.00 7.00 0.02 1.84 1.18 0.1420.004.732.207.000.02 1.3450.690.088.0035.1412.9551.910.00 Poole U3 4.56 1.50 9.00 0.02 4.25 2.15 0.1223.004.560.608.000.02 3.1652.120.0912.0027.8915.3156.800.00 Poole U4 4.67 1.60 5.00 0.02 6.04 3.36 0.1016.004.651.704.000.02 3.3353.370.063.0027.5413.5258.940.00 Poole U5 4.74 2.00 7.00 0.03 6.47 3.63 0.118.004.732.106.000.03 5.4253.840.135.0021.3117.7460.960.00 South Oropouche L1 5.96 12.00 11.00 0.13 8.93 5.83 9.6039.005.924.9011.000.15 7.3005.647.8524.0043.0525.5431.410.00 South Oropouche L2 6.02 5.70 21.00 0.10 8.77 5.12 0.3620.005.824.1018.000.10 8.4554.880.3621.0031.7420.2248.030.00 South Oropouche L3 4.92 11.90 7.00 0.08 10.41 5.37 0.4121.004.9110.907.000.07 8.7255.790.2215.0057.1815.0027.820.00 South Oropouche L4 4.97 12.40 2.00 0.07 7.93 4.33 0.1515.004.699.602.000.07 9.5455.050.137.0065.0519.4015.550.00 South Oropouche L5 4.89 13.20 6.00 0.08 8.55 4.79 0.2920.004.6611.103.000.07 9.7854.970.168.0066.6820.4012.920.00 South Oropouche M1 5.49 1.30 14.00 0.04 6.00 3.58 0.2228.005.751.2013.000.03 6.6003.870.2829.0027.5641.6130.840.00 South Oropouche M2 5.63 1.80 12.00 0.03 5.76 4.58 0.1612.004.731.809.000.03 4.9403.980.1314.0034.5435.1530.310.00 South Oropouche M3 5.23 1.30 5.00 0.05 6.93 4.60 0.1514.004.671.305.000.05 5.7253.990.1015.0042.1215.6342.250.00 South Oropouche M4 5.17 1.30 4.00 0.05 4.58 3.38 0.1115.005.051.805.000.04 4.7553.610.087.0017.4934.6647.850.00 South Oropouche M5 5.13 1.70 10.00 0.05 5.82 4.49 0.3620.005.140.907.000.05 5.6204.370.105.0045.1614.1840.660.00 South Oropouche U1 6.15 1.10 9.00 0.05 7.58 3.68 0.1324.005.830.907.000.04 6.3103.590.1617.0046.8022.4930.710.00 South Oropouche U2 5.11 2.00 4.00 0.05 7.28 4.33 0.1540.005.241.903.000.04 6.9654.220.2023.0049.3714.1836.450.00 South Oropouche U3 4.67 0.90 2.00 0.05 2.95 2.96 0.0628.004.781.403.000.05 1.9302.530.063.0050.5126.4823.010.00
218River Reach Block pH (30 cm) N (30 cm) (g kg-1) P(30 cm) (mg kg-1) K(30 cm) (c mol kg-1) Ca(30 cm) (c mol kg-1) Mg(30 cm) (c mol kg-1) EC (30 cm) (mS cm-1) OC (30 cm) (g kg1) pH (60 cm) N (60 cm) (g kg-1) P(60 cm)(mg kg-1) K(60 cm) (c mol kg-1) Ca(60 cm) (c mol kg-1) Mg(60 cm) (c mol kg-1) EC (60 cm) (mS 1) OC (60 cm) (g kg1) % clay % sand % silt % gravel South Oropouche U4 4.76 1.90 2.00 0.04 3.20 3.06 0.0915.004.860.503.000.04 2.5753.090.077.0045.1424.4330.430.00 South Oropouche U5 4.36 2.50 7.00 0.03 0.82 1.60 0.088.004.711.604.000.05 1.1452.230.077.0042.1924.8632.950.00 xx= missing data; n=negligible values. L=lower reach, M= Middle Reach, U= Upper Reach
219 APPENDIX F SPECIES FOUND AT ONLY ONE SITE
220 River Upper Reach Middle Reach Lower Reach Chrysothemis pulchella (Donn) Decne. Carica papaya L. Cassia reticulata Willd Hypoderris brownii J.Sm. Digitaria ciliaris (Retz.) Koeler Hymenachne sp. Poaceae 4 Cleome rutidosperma DC. Ludw igia peruviana (L.) H. Hara Rorippa nasturtium-aquaticum (L.) HayekIschaemum timorense Kunth Mimosa casta L. UT14 Peperomia pellucida (L.) Kunth UG19 Boehmeria ramiflora Jacq. Pilea microphylla (L.) Liebm. UG20 Ficus yaponensis Desv Rorippa sinapis (Burm. f. ) Ohwi & H. Hara Setaria barbata (Lam.) Kunth Eleusine indica (L.) G aertn. Commelina erecta L. Lauraceae 1 Ludwigia sp. 1 Portulaca quadrifida L. Aripo UG21 Annona squamosa L. Blechnum occidentale L. Conyza apurensis Kunth Ceiba pentandra (L.) Gaertn. Chrysopogon zizanioides (L.) Roberty Cyperus surinamensis Rottb. Lauraceae 2 Clidemia sp. 1 Eclipta prostrata (L.) L. Manilkara bidentata (A. DC.) A. Chev. Combretum fruticosum (Loefl.) Stuntz Heliotropium indicum L. Vismia cayennensis (Jacq.) Pers. Enicostema vertic illatum (L.) Engl. ex Gilg Muntingia calabura L. Zingiber officinale Roscoe Miconia sp. Pennisetum sp. N eurolaena lobata (L.) Cass. UG23 Persea americana Mill. Ludwigia erecta (L.) H. Hara UG14 Alysicarpus vaginalis (L.) DC. UG22 Gonzalagunia hirsuta (Jacq.) Schumann Pouteria multiflora (A. DC.) Eyma Psidium guajava L. Cocos nucifera L. Coursetia arborea Griseb Arouca Mammea americana L.
221 River Upper Reach Middle Reach Lower Reach Echinochloa colona (L.) Link Lantana trifolia L. Condylidium iresinoides (Kunth) R.M.King & H.Rob Leptochloa virgata (L.) P. Beauv. UG13 Dichanthium caricosum (L.) A. Camus Oxalis frutescens L. UG16 Malachra fasciata Jacq. Piper sp.2 UG17 UG8 Triumfetta althaeoides Lam. Setaria sp. Mimosa pigra L. Caparo UG24 Crudia glaberrima (Steud.) J.F. Macbr Annona muricata L. Abildgaardi a ovata (Burm. f.) Kral Cordia alliodora (Ruiz & Pav.) Oken Coccoloba sp.1 Cordia bicolor A. DC. Hirtella racemosa Lam. Erythrina variegata L. Hirtella triandra Sw. Mikania hookeriana var. platyphylla (DC.) B.L. Rob.Philodendron acutatum Schott UG11 Pouteria minutiflora (Britton) Sandwith Manilkara zapota (L.) P. Royen Psychotria patens Sw. UT16 Swartzia simplex (Sw.) Spreng. Cedrela odorata L. Tabern aemontana undulata Vahl Teliostachya alopecuroidea (Vahl) Nees Trichomanes pinnatum Hedw. UG2 UG25 UG26 UT1 UT36 Ageratum conyzoides L. Isertia parviflora Vahl Lacistema aggregatum (P.J. Bergius) Rusby Lygodium volubile Sw. Schizaea elegans (Vahl) Sw. UT15 Abarema jupunba (Willd.) Britton & Killip Psychotria poeppigiana Mll. Arg. Caura Miconia punctata (Desr.) D. Don ex DC.
222 River Upper Reach Middle Reach Lower Reach Gibasis geniculata (Jacq.) Rohweder Anacardium occidentale L. Poaceae 1 Ludwigia decurrens Walter Poaceae 6 UG31 Priva lappulacea (L.) Pers. Securidaca diversifolia (L.) S.F. BlakeMachaerium tobagense Urb. UG27 Couva UT8 Justicia pectoralis Jacq. Mikania sp.1 UG33 Euterpe oleracea Mart. Pterolepis glomerata (Rottb.) Miq. UG34 Hyptis atrorubens Poit. Urera baccifera (L.) Gaudich. ex Wedd. UG36 Monstera sp. Commelina diffusa Burm. f. UG 35 Simarouba amara Aubl. Zanthoxylum martinicense (Lam.) DC. Cyperus sp. UG32 Cumuto Leptochloa longa Griseb. Ludwigia sp. Swietenia macrophylla King Bignoniaceae 4 UG38 Cissus sp. Dioclea reflexa Hook. f. UG39 Clidemia sp. 2 Drymonia serrulata (Jacq.) Mart. Costus sp. Marsdenia macrophylla (Humb. & Bonpl. ex Schult.) E. Fourn. Lasiacis ligulata Hitchc. & Chase UG37 Mikania scabra DC. Palicourea crocea (Sw.) Roem. & Schult. Passiflora serratodigitata L. Lebranche Pterocarpus officinalis Jacq. Reach River Upper Middle Lower Crateva tapia L. Cleome spinosa Jacq. Celestraceae 2 Cyclopeltis semicordata (SW.) J.Sm. Wedelia tr ilobata (L.) Hitchc. Cleome gynandra L. Lomariopsis japurensis (Mart.) J.Sm. Terminalia dichotoma G. Mey. Croton lobatus L. Pavonia castaneifolia A. St.-Hil. & Naudi nPiper hispidum Sw. Guarea glabra Vahl Trema micrantha (L.) Blume Heliotropium angiospermum Murray UT18 Lastreopsis effusa (Sw.) Tindale var divergens (Willd. Ex Schkuhr) UT19 Senna sp. Mill. Pharus latifolius L. UG40 UG12 UG9 Piresia sympodica (Dll) Swallen UT11 Moruga Heliconia spatho-circinada Aristeg. UT17
223 River Upper Reach Middle Reach Lower Reach Mouriri rhizophor ifolia (DC.) Triana Adiantum pulverulentum L. Leptochloa sp. Asplundia rigida (Aubl.) Harling A canthaceae Eugenia monticola (Sw.) DC Dendropanax arboreus (L.) Decne. & Planch Piper hispidum UG46 Diplazium grandifolium (Sw.) Sw. Pothomorphe peltata ( L. ) Miq. UT20 Ficus amazonica (Miq.) Miq. UG6 UT21 Miconia nervosa (Sm.) Triana Panicum maximum Jacq. UT22 Ocotea eggersiana Mez Quiina cruegeriana Griseb. Ryania speciosa Vahl Thelypteris serrata (Cav.) Alston UT2 UT23 UT24 UT3 UT4 UT5 UT9 Xanthosoma undipes (K. Koch & C.D. Bouch) K. Koch Calophyllum lucidum Benth. Chimarrhis cymosa Jacq. Psychotria capitata Ruiz & Pav. Cyathea sp. Hernandia sonora L. Hieronyma laxiflora (Tul.) Mll. Arg. Manicaria saccifera Gaertn. N orth Oropouche Cnemidaria spectabilis (Kunze) R.M. Tryon Reach
224 River Upper Reach Middle Reach Lower Reach Diospyros inconstans Jacq. Capparis ba ducca L. Bursera simaruba (L.) Sarg. Machaerium robiniifolium (DC.) Vogel Eugenia baileyi Britton Chionanthus compactus Sw. Tectona grandis L. f. Morisonia americana L. Crescentia cujete L. UG42 Eugenia sp.1 UG47 Leguminosae UT27 Phryganocydia corymbosa (Vent.) Bureau ex K. Schum. Lauraceae 4 Sansevieria hyacinthoides (L.) Zanthoxylum microcarpum Griseb. UG18 UT26 UG3 UG41 UT25 Desmoncus orthacanthos Mart N ectandra rectinervia Meisn. Penal Paullinia leiocarpa Griseb. Paullinia pinnata L UG45 Lauraceae 3 Solanaceae UG48 Myrcia splendens (Sw.) DC. UT7 UG1 UG10 UG7 UT28 UT32 UT30 UT33 UT31 UT29 Poole Buchenavia tetraphylla (Aubl.) R.A. Howard Paullinia pinnata L Erio chloa punctata (L.) Desv. ex Ham. Bignoniaceae 2 Solanaceae Heliotropium procumbens Mill Hy menachne amplexicaulis (Rudge) Nees UT7 Merremia umbellata (L.) Hallier f. Imperata brasiliensis Trin. UG28 UG5 Urochloa mutica (Forssk.) T.Q. Nguyen South Oropouche Terminalia catappa L.
225 APPENDIX G ORDINAL VARIABLE RANKINGS AND JUSTIFICATIONS
226Reach Level of recreation Recreation rank j ustification Level of channel modification Channel modification rank justification Level of pollution Pollution rank j ustification Level of fire Fire rank Justification ARIL 1 Trails 0 0 0 ARIM 3 sheds, cooking, bathing 2 large number of pools created by placing concrete columns in the river 3 algae, fertilizers, solid waste 0 ARIU 1 bathing 2 tributaries were dammed for water cress production 1 solid waste 0 AROL 0 4 dredging resulting in vegetation removal and changes to slope and channel morphology 2 solid waste and stench 0 AROM 1 bathing 0 1 solid waste 0 AROU 1 bathing 0 1 solid waste 0 CAPL 0 4 dredging resulting in vegetation removal and changes to slope and channel morphology 2 solid waste and stench 2 repeated burnings for agriculture
227 Reach Level of recreation Recreation rank j ustification Level of channel modification Channel modification rank justification Level of pollution Pollution rank j ustification Level of fire Fire rank Justification CAPM 1 trails 4 dredging resulting in vegetation removal and changes to slope and channel morphology 1 solid waste 2 repeated burnings for agriculture CAPU 0 4 dredging resulting in vegetation removal and changes to slope and channel morphology 1 solid waste 2 repeated burnings for agriculture CAUL 2 playground, wading 4 dredging resulting in vegetation removal and changes to slope and channel morphology 2 solid waste, stench 1 isolated burnt patch CAUM 3 bathing, cooking, firewood 0 1 solid waste 0 CAUU 1 bathing 0 0 0
228 Reach Level of recreation Recreation rank j ustification Level of channel modification Channel modification rank justification Level of pollution Pollution rank j ustification Level of fire Fire rank Justification COUL 0 0 1 solid waste 3 repeated burnings for agriculture, also proximity near road and evidence of none non agric related fires COUM 0 0 2 solid waste, sespit 1 isolated patch COUU 1 cooking 0 1 solid waste 0 CUML 0 0 0 0 CUMM 0 4 dredging resulting in vegetation removal and changes to slope and channel morphology 0 0 CUMU 0 0 0 0 LEBL 0 0 1 solid waste 0 LEBM 0 0 1 solid waste 0 LEBU 0 0 0 0 MORL 1 hunting 0 0 0 MORM 1 hunting 0 0 0 MORU 1 hunting 0 0 0
229 Reach Level of recreation Recreation rank j ustification Level of channel modification Channel modification rank justification Level of pollution Pollution rank j ustification Level of fire Fire rank Justification NORL 2 recreational drug use, trails 4 dredging resulting in change in slope, morphology and also vegetation removal 1 solid waste 0 NORM 0 0 2 solid waste, stench 0 NORU 1 bathing 0 0 0 PENL 1 hunting 0 0 0 PENM 1 hunting 0 0 1 isolated patch PENU 1 hunting 0 0 3 fires repeated burnings POOL 1 trails 0 1 solid waste 0 POOM 1 hunting 0 0 0 POOU 0 0 0 2 close to road and evidence of more than one burning SOUL 2 trails, fishing 3 dredging resulting in change in slope, morphology and also vegetation removal. Dredging was not recent unlike the other sites. 1 solid waste 2 repeated burnings for agriculture SOUM 0 4 2 solid waste and stench 2 repeated burnings for agriculture SOUU 0 0 1 solid waste 2 repeated burnings
230 APPENDIX H CRITERIA FOR RANKING RIPARIAN ZONE AND UPL AND EDAPHI C MODIFICATION
231 Rank Criteria 0 No trails, skidder trails, bu ildings, drains, furrows, beds, wooden buildings, di rt, gravel, or paved ro ads, concrete drains or concrete buildings. 1 Trails and skidder trails present. No buildings, drains, furrows, beds, wooden build ings, dirt, gravel, or paved roads, concrete drains or concrete buildings. 2 Evidence of past modification, for example, overgrown trails, skidder trails, buildings, drains furrows, beds. No signs of active maintenance or modification. No perman ent structures, for example, concrete buildings. 3 Evidence of recent or current site modification, for example, bare earth, bulldozing, furrows, beds, non-concrete buildings and dirt roads. Signs of active maintenance of the aforementioned. 4 Permanent site modification, for example, impervious land cover paved roads, gravel roads, concrete drains, metal pipes, concrete buildings..
232 APPENDIX I SIGNIFICANT CORRELATIONS AMONG E NVIRONMENTA L AND ANTHROPOGENIC VARIABLES USED IN BIOENV ANALYSES
233 Clay catchment length(km) Maximum basin relief K(30 cm) (cmol kg-1) Ca(30 cm) (cmol kg-1) Mg(30 cm) (cmol kg-1) EC (30 cm) (mS cm-1) ph (60 cm) P (60 cm) (mg kg-1) Sand -0.781(**)-0.264(**) 0.474(**)-0.580(**) -0.209(*) -0.610(**)-0.138 0.200(*) -0.076 relief ratio H/L -0.518(**)-0.692(**) 0.880(**)-0.300(**) -0.208(*) -0.593(**)-0.017 0.167 -0.285(**) area km2 0.368(**)0.790(**) -0.205(*) 0.336(**) 0.17 0.449(**)0.061 -0.123 0.336(**) form factor (area/l2) 0.281(**)-0.259(**) 0.074 0.462(**) 0. 087 0.091 0.204(*) -0.068 -0.199(*) % forest cover 1994 -0.215(*) -0.378(**) 0.315(**)-0.088 -0.183 -0.415(**)0.071 -0.15 -0.295(**) ph (30 cm) -0.322(**)-0.208(*) 0.278(**)-0.270(**) 0. 598(**) -0.037 0.395(**)0.889(**)0.321(**) P(30 cm) (mg kg-1) 0.045 0.321(**) -0.02 -0.026 0.386(**) 0.328(**)0.342(**)0.338(**)0.882(**) K(60 cm) (c mol kg-1) 0.703(**)0.093 -0.390(**)0.901(**) 0.303( **) 0.679(**)0.274(**)-0.233(*) 0.081 Ca (60 cm) (c mol kg-1) 0.188 0.116 -0.152 0.228(*) 0.955(**) 0.485(**)0.539(**)0.628(**)0.374(**) Mg(60 cm) (c mol kg-1) 0.630(**)0.339(**) -0.501(**)0.630(**) 0. 469(**) 0.969(**)0.375(**)0.023 0.350(**) 0.153 -0.005 0.041 0.190(*) 0.568(**) 0.345(**)0.862(**)0.495(**)0.384(**) EC (60 cm) (mS cm-1) Variables highlighted with correlatio ns >0.7 at p<.001 were eliminated. significant at p<0.01, ** significant at p<0.001
234 APPENDIX J RAPID RIPARIAN ZONE ASSESSMENT PROTOCOL FOR TRINIDAD Instructions 1. Measure a sample block 30 m long x 30 m wide on one side of the river channel starting at the waters edge. Each side of the river should be done separately. 2. Take photos of river channel a nd the vegetation from the riverb ank to end of the transect. 3. Record the data in Section B below and sum the results provide determine the site management strategy. 4. Determine priority levels for re storation sites using Section C. 5. Use Section D for any additional notes. Section A: General site data Date: GPS UTM coordinates: Person recording data:
235 Section B: Site integrity and defensibility Section Variable category Variable rating Score Exotic tree species a) No Bambusa vulgaris (10) b) Bambusa vulgaris present (0) Exotic and weedy ground flora species a) No Sorghum sp. or Pureria phaseoloides (5) b) Either Sorgum sp. or Pureria phaseoloides present (2) c) Both Sorghum and Pureria present (0) Secondary vegetation indicator species a) One or more of the follo wing species present (5) Cecropia peltata Ochroma pyramidale Spondias mombin Hura crepitans b) None of the above species present (0) 1. Biological integrity No. of tree species a) > 20 (10) b) 11-20 (6) c) 6-10 (4) d) 1-5 (2) e) 0 (0) Biological Integrity Subtotal 2. Site defensibility Disturbance a) Forest-No buildings, drains, furrows, beds, wooden buildings, dirt, gravel, or paved roads, concrete drains or concrete buildings. No agricultural species. Trees are irregularly spaced, i.e. not in rows which are indicative of abandoned agricultural estates Site has canopy cover (10) b) Secondary Vegetation-Site has canopy cover. Agricultural species may be present, planted in rows with heavy unmaintained undergrowth. Evidence of past modification may be present, for example, overgrown trails, buildings, drains, furrows and agricultural beds (6) c) Grassland-No canopy cover. No active weeding or site maintenance. No buildings, drains, furrows, beds. No dirt, gravel, or paved roads (3) d) Agiculture-Cultivated species present. Evidence of site maintenance, for example, weeding or little undergrowth under crop species. Site may gave bare earth, beds, nonconcrete buildings and dirt roads. e) Developed-Evidence of permanent site modification, for example, impervious land cover like paved roads, gravel roads, concrete drains, metal pipes, concrete building. Grass or ornamental plants may be present but must show signs of maintenance, for example, mowing. (0)
236 Upland Disturbance 50-100 m from river channel edge f) Forest-No buildings, drains, furrows, beds, wooden buildings, dirt, gravel, or paved roads, concrete drains or concrete buildings. No agricultural species. Trees are irregularly spaced, i.e. not in rows which are indicative of abandoned agricultural estates Site has canopy cover (10) g) Secondary Vegetation-Site has canopy cover. Agricultural species may be present, planted in rows with heavy unmaintained undergrowth. Evidence of past modification may be present, for example, overgrown trails, buildings, drains, furrows and agricultural beds (6) h) Grassland-No canopy cover. No active weeding or site maintenance. No buildings, drains, furrows, beds. No dirt, gravel, or paved roads (3) i) Agiculture-Cultivated species present. Evidence of site maintenance, for example, weeding or little undergrowth under crop species. Site may gave bare earth, beds, nonconcrete buildings and dirt roads. j) Developed-Evidence of permanent site modification, for example, impervious land cover like paved roads, gravel roads, concrete drains, metal pipes, concrete building. Grass or ornamental plants may be present but must show signs of maintenance, for example, mowing. (0) Evidence of fire Presence (0) Absence (50) Site defensibility Subtotal 4. Total integrity and defensibility score Total integrity and defensibility score Management strategy recommended >80 (Conserve) 50-79 (Possible restoration site) <50 (Leave as is) Section C: Site restoration priority levels Restoration Priority (High, Medium, Low) Channel modification a) Evidence of dredging or channelization at the site or dams upstream (Low priority) b) Other forms of channel modification which would still allow flooding, for example, pool c reation (Medium priority) c) No evidence of channel modification (High priority) Section D Additional notes
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246 BIOGRAPHICAL SKETCH Natalie Boodram is a citizen of Trinidad and Tobago. She has a first degree in Botany and a M.Phil. in plant science both obtained from the Un iversity of the West Indies in Trinidad and Tobago. Prior to her Ph. D. program, she worked at the Caribbean Environmental Health Institute (CEHI), an inter-governmental agen cy, based in St. Lucia, which carries out environmental work in 16 Caribbean countries. Sh e has served as an ecologist for a number of environmental impact assessment (EIA) companies in the Caribbean, and worked as an Environmental Education Officer at the Pointe-a-Pierre Wild Fowl Trust in Trinidad and Tobago. She has also worked at the Center fo r Gender and Development Studies in Trinidad where she carried out research on Gender and th e Environment issues. After her Ph.D., she will continue her work in environmental management in the Caribbean.