Title: Diversity of Wetands in Florida; A Concern for Regulation
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Permanent Link: http://ufdc.ufl.edu/WL00000860/00001
 Material Information
Title: Diversity of Wetands in Florida; A Concern for Regulation
Physical Description: Book
Language: English
Spatial Coverage: North America -- United States of America -- Florida
Abstract: Diversity of Wetands in Florida; A Concern for Regulation By: Richard J. Callahan, Jr.
General Note: Box 7, Folder 3 ( Vail Conference 1988 - 1988 ), Item 31
Funding: Digitized by the Legal Technology Institute in the Levin College of Law at the University of Florida.
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Bibliographic ID: WL00000860
Volume ID: VID00001
Source Institution: Levin College of Law, University of Florida
Holding Location: Levin College of Law, University of Florida
Rights Management: All rights reserved by the source institution and holding location.

Full Text


3819 ERST 71 AvsU
AaJM, FII 33605


Florida has between 2.5 and 2.75 million acres of freshwater systems which

account for an abundance of wetland habitat. Freshwater wetlands in Florida are
highly variable in form and function. The degree of variability is influenced on
a local level by soils, topography and hydrology. Freshwater wetland conmcnities
vary significantly in ouaposition from region to region as they are affected by
climate and hydrologic regimes.

Defining wetlands and determining their extent has became a universal dilemma

for numerous entities in the state. Differences in philosophy, methodology and

Special interests continue to promote subjective ambiguity in the quest for
a perfected quantitative approach for defining and delineating wetlands. Regional
differences in species composition, soils and hydrology hinder the applicability

of a statewide methodology that relies on a master plant species list and

generalized hydrologic guidelines.


Wetlands are generally recognized as areas where the water table is at, near
or above land surface for a significant part of the year (Anderson, 1975). Water
is the primary factor controlling wetland envir moments and their associated flora

and fauna (Niering, 1985). Several regulatory agencies have adopted their own
definitions of wetlands and supported them with legislation. Presently there are

two Federal definitions for wetlands. One was established by the U.S. Fish and
fr Wildlife Service for mapping and classifying wetlands. The second definition


employed by the U.S. Army Cops of Engineers and the Environmental Protection

Agency for regulation is more restrictive. The differences in the two definitions
accounted for the USFWS estimating there were 99 million acres of wetlands in the
lower 48 states in the mid-1970's while the U.S. Army Corps of Engineers (ODE)
concurrently estimated the acreage at 64 million acres (Gibbons, 1984).

Currently, anywhere in Florida there are at least three overlapping wetland
regulatory agencies with varying definitions of wetlands and methodologies for
their delineation. They include, but are not restricted to the ODE, Florida
Department of Enviraental Regulatio (IER) and the Water Management Districts
(WMD). Numerous local governments have even more inclusive criteria for
determining wetland limits specified in ordinances and rules.

The focus and protection afforded freshwater wetlands is to preserve the
tangible and intangible benefits they provide for our environment. Those benefits
include but are not limited to:
attenuate floodwaters
prevent erosion
recharge groundwater and piezometric supplies

enhance water quality
reduce air pollution
wildlife habitat

forestry products
support fisheries
S aesthetics


The benefits realized from each type of wetland may vary significantly with the
inherent dynamics of the biotic and physical characteristics of the system.

Freswater wetlands are generally classified as lacustrine (associated with
lakes), riverine (river floodplain) or palustrne (marshes and swamps). There are
many variations of each classification. Those variations are recognized by
differences in the floral constituency which are the result of subtle differences
in hydrology, soils, topography, and water chemistry. Under varying conditions
the above parameters promote the dominance of certain species and the exclusion of
others. The physical parameters of freshwater wetlands in Florida differ
significantly from region to region, particularly when ccuparing the southern
portion of the state with the Panhandle.


Florida is characterized by a diverse climatic, geologic and biotic
conditions. Peninsular Florida is only 100 miles from the tropics. The sub-
tropical climate of South Florida is very different from the temperate conditions
in North Florida. Florida's average annual rainfall of 53 inches is variable from
coast to coast.

Coastal areas in all parts of the state average slightly warmer temperatures
in winter and cooler temperatures in summer than inland areas at the same
latitude. Ihe Gulf Stream on the east coast and Gulf of Mexico on the west coast
buffer coastal temperatures. Average winter temperatures vary by about 10 degrees
from north to south (Marth, 1985). The most significant climatic influence on the


distribution of biotic cauinities is the freguncy of freezes. Occurrence of
hard freezes below the middle latitudes of the state are uncrmon.

Rainfall is a significant factor in the formation and perpetuation various
wetland types. Rainfall averages across the state are not significantly different
(Marth, 1985). The heterogeneous hydrologic conditions in the state are due to
variable topographic and other geologic features.

The greater topographic relief and more prevalent irregular contours in the
northern and central portions of the state promote the development of high
velocity, dynamic flowing systems based on spring and surface water flows. The

relatively flat basin conditions of the coastal and southern regions of the state
are typified by slow moving waterbodies fed by underground and surface water


Geologic formations account for hydrologic contributions to wetlands. Soil
types are developed from the interactions of geologic features with hydrology and

climate. The porous limestone plateau below and at land surface in various

regions of the state is dynamic. Spring flows, sinks, rock out crppings and
the broad everglades basin we all associated with the porous limestine plateau
that is "spine" of the state. These systems support specific wetland

A major influence of species richness in wetlands is spatial heterogeneity.
The mre niches the more opportunity for colonization of a new species (Jacobs,


1975). Hydrologic regime is the major factor affecting spatial diversity
(Gosselink, 1978). Flooding waters have the effect of minimizing spatial
diversity because of uniform mixing. Cmisquently, the biotic community of
an expansive flat basin wetlands such as the Everglades are depauperate in
comparison to the oommunities found in the dynamic high velocity spring runs of
central and northern Florida.

Diversity in wetlands is a function of flooding duration and depth.
Diversity generally increases with elevation. Increased water velocity also
increases plant species richness. Consequently, a hydrologic regime can promote
uniformity in the biotic system or lead to greater diversity (Gorham, 1957). The
heterogeneity of the hydrologic regimes in Florida variable species composition
and diversity within associated wetland floral communities.

Florida's freshwater wetlands are typically described to a cacmunity level
during most assesmnts. Finer distinctions can be made within communities to
emphasize dominant species. Subtle differences in climate and hydrologic regime
can affect significant changes in floral species dominance and composition.

The most ocmnanly employed classification system for freshwater wetlands is
the Florida land Use. Cover and Forms Classification System produced by the
Florida Departmnt of Trasportation. Broad classifications for wetlands
are wetland hardwood forest, wetland coniferous forest, mixed wetland forest and
vegetated non-forested wetlands. The system more specifically identifies 12
different freshwater wetland ocmunities. lhey are:



bay swamps

- gum swamps
titi swamps

stream/lake swamps


m- iad hardwoods

- cypress swamps

pond pine swaps

Atlantic white cedar swamps

cypress pine cabbage palm swamps

freshwater marshes

wet prairies

Bay Swamps

This category is composed of dominant trees such as loblolly bay, sweetbay,

red bay, swamp bay, slash pine and loblolly pine. large gallberry,

fetterbsh, wax myrtle and titi are included in the understory vegetation

Gum Swamps

7his forest oc anmity is ccnposed of wauap tupelo (blackgum) or water tupelo

(tupelogum) which is pure or predominant. Associate species may include bald

cypress and a great variety of wet site tolerant hardwood species widely

variant in opposition.


Titi Swamps
This ocmmnity is ccmponed of often extremely dense stands of black titi and

cyrilla which are either the pure or predminant species. Major associated

species include bays, cypress, tupelos and a great variety of wetland


Stream and ake Swamps (Bottdoland)
This community, often referred to as bottmland or stream hardwoods, is
usually found on but not restricted to river, creek and lake flood plain or

overflow areas. It is a conglomeration of a wide variety of predominantly
hardwood species of which same of the more oamoon components include red

maple, river birch, water oak, sweetgum, willows, tupelos, water hickory,
bays, water ash and buttonbush. Associated species include cypress, slash

pine, loblolly pine and shortleaf pine.

Inland Ponds and Sloughs
these ocnmunities are associated with depressions and drainage areas that are
not associated with streams or lakes. On or a ocIbination of the following

species will generally be predominant: pond cypress, swap tupelo, water
tupelo, titi or willows.

Mixed Wtland Hardwoods
This category is reserved for those wetland hardwood communities which are
mnpesfi of a large variety of hardwood species tolerant of hydric conditions

yet exhibit an ill defined mixture of species.

A/ 9/


This mcmunity is ccnposmd of pond cypress or bald cypress which is either

pure or pr edminant. In the case of pond cypress, camo associates are

suwmp tupelo, slash pine and black titi. In the case of bald cypress, camn

associates are water tupelo, swam cottomood, red maple, American elm,

pmpkin ash, Carolina ash, overcup oak, and water hickory. Bald cypress may

be associated with laurel oak, seetgum and sweetbay on less moist sites.

Note that some authorities do not distinguish between two varieties of


PFnd Pine

This category is ccnposed of pond pine which is either pure or predominant.

Its major associate is titi. Minor associates include sweetbay, loblolly

bay, red bay, and swamp tupelo.

Atlantic White Cedar

In this community, Atlantic White Cedar is the indicator species although it

may not always be the most abundant. Its omnon associates include slash

pine, cypress, swamp tupelo, sweetbay, red bay, loblolly bay, titi and red


Cypress Pine Cabbage Palm

his ocmunity includes cypress, pine and/or cabbage palm in combinations in

which neither species achieves dominance Although not strictly a wetlands

ooammnity, it forms a transition between moist upland and hydric sites.

Freshwater Marshes

The omamnities included in this category are characterized by having one or

more of the following species Ipedm inate:

Sawgrass mLadium mncs
cattail a inenis

Ch latifolia

Eba anoustifolia

Arrohbead Saaittaria sp.

Maidencane Panicum hemAitmn

Buttcnbush Oeghalanths ocidentalis

Oordgrass Spartina ba.eri

Switdgrass anicum viratum

Bulrush Scirpus americanus

Scirpus validus

Scirpus nabstus
Needlerush Juncus efusus

cmaon eed Phramnites commnis

Phramaites australis

Arrawroot Thalia dealata

Ihalia aeniculata

Wet Prairie

This classification is ncupo.ai of dominantly grassy vegetation on wet soils

and is usually distinguished frc marshes by having less water and shorter

herbage. These cammities will be predaminated by one or more of the

following species:




Spike aRshes

Beach Rushes
St. Johns Wort


Yellow-eyed Grass

Whitetop sedge

- Caium lamicensis

- Panicum hemitrano

- Spartina bakeri

Spartina atUns
- Eleocharis sp.

- IvreD Up.

- Dirir mga

(FDOT, 1985)

Same of the specified camunities such as titi swamps and pond pine swamps

are restricted geographically in the state. Their limitations are a factor of the

dominant species intolerance for the sub-tropical climate in central and southern

Florida. All the other ocmunities vary within their broader classifications in

response to influential factors such as hydrologic regime, soils, climate and

water chemistry.

Floral species dominance is readily discernable in a cursory review and

generally the basis for naming a specific wetland cx unity. Differences in

species composition and diversity within the same ammmnity in different regions

of the state is not addressed in most asaismn mnts. Recent assessments by

Biological Research Associates, Inc. (BRA) in north, central and southern Florida




have revealed as much as a 10 percent variation of species opposition in
freshwater marshes. Similar variability was observed in wet prairies and slough


Species dominance in the eootones (transitional areas) of each of the above
wetland systems investigated was variable. Slight differences in hydrologic
conditions, soils and topography influenced significant changes in composition,
and dominance in ecotone associations.

Significant fluctuations in species diversity, dominance and distribution
within most types of wetlands can occur over a relatively short period of time.
Seasonal conditions, drought and flood can affect as much as a 50 percent change
in camposition over a 12 month period in a wetland (Callahan, 1986).
Similar fluctuations in plant diversity and composition occur in non-contiguous
wetlands routinely on a seasonal basis. The most dramatic changes are observed in
the ectcones.

Decades of draining, mining and agricultural development have perturbed the
physical integrity of vast acres of freshwater wetlands in Florida. In addition
sane introduced exotic plant and tree species have rapidly invaded the forested
and non-forested wetlands throughout the state. The most heavily infested areas
are in South Florida where punk trees (elala inuenervia), eucalyptus
(Eucaltus app.) and Brazilian pepper (Schinus terebinthifolius) often dominate
the transition areas of wetlands.




Dematering and disruption of natural substrates and inherent seed banks
often open the door for exotic species invasion. In the absence of exotic
invaders native species opposition, diversity and cover is typified by
opportunistic invaders such as cattails (Tvha qp.), primrose willow (ITdwiMia

spp.) and torpedo grass (Panium ees). Ihese prolific plants frequently
suxeed to a near mnoculture representation in the system diminishing some of the
positive function attributed to wetlands.

These altered systems are technically wetlands in form and function, but
offer less desirability when ocupared to unpeturbed wetlands. Defining and
delineating altered wetlands is often tedious and frustrating. The merits of
identifying and protecting severely altered wetlands are questionable. When
hydrologic indicators are not conducive to perpetuating desirable wetland
attributes the system no longer functions and should not be classified or
delineated. Hydrology is the key factor in wetland development and function.

Regulatory groups throughout the State appear to be investigating and/or
adopting a three parameter approach to define and delineate wetlands. The
technique addresses wetlands as lands that are transitional between terrestrial
and aquatic systems with the following three conditions:' (1) at least
periodically the land supports hydryphytes; (2) the substrate is a hydric soil;
and (3) the substrate is saturated with water or covered by shallow water at same
time daring the growing season each year (Omawrdin, 1979).

SProblems arise using the three parameter approach when regulatory groups
pportunistically focus on one or two conditions for a wetland determination, in



( general all systems should eodibit the three of the above conditions to be
classified as a freshater wetland. There can be sections to this general
approach. Altered wetlands where vegetation ard/or soils have been displaced or
destroyed must be given special casideration. Hydrperiod becomes a primary
factor in assessing altered systems. Ihe likelihood that a viable wetland
cmiunity will develop from a disturbed system in a natural setting is almost
entirely dependent on hydrologic odlitions.

Another source of dispute in the three parameter approach, and almost all
other methods currently employed in the state to define and delineate wetlands is
the reliance on a state wide list of submerged and transitional indicator plant
species for dominance determinations. he criteria for determining the dominance
of transitional and submerged species under DER's regulations (17-4) are
significantly different frcu the OOE's guidelines (Section 404) as is their
respective plant lists. The presence of cosmopolitan species that frequently are
found in uplands as well as wetlands on both agencies' lists reduce the accuracy
of the methodology.

Regional variability of plant species ccaposition in various wetland

mmmunities make the utilization of a statewide methodology and plant list

questionable when considering specific local conditions. A regional program may
more aurately define and delineate wetlands considering local physical and
biotic characteristics.


Anderson, J.R., Hardy, E.E., Roach, J.T., and Witmer, R.E., 1975. A Land-Use and
land-Cover Classification System for Use with Remote-Sensor Data: U.S. Geol.
Survey Circ. 727.

Callahan, R., Hanners, L., and Patton, S., 1986. Ecological Monitoring Report for
the Cross Bar Ranch Regional Wellfield. Tampa, Florida: Biological Research
Associates, Inc., Vol. 7, 124 p.

Ciwardin, L.M., Carter, V., Golet, F.C., and LaRoe, E.T., 1979. Classification of
Wetlands and Deepater Habituals of the United States, Washington D.C.: U.S.
Dept. of Interior, Offices of Biological Services Fish and Wildlife Service,
103 p.

Florida land Use, Cover and Forms Classification System, 1985.
of Transportation, 33 p.

Gibbons, J.H., 1984. Wetlands: Their Use and Regulation, Was
Congress, Office of Technology Assessment, 206 p.

Gorham, E., 1957. The development of peat lands.
pp. 145-166.

Florida Department

hington D.C.:

Quart. Rev. Biol.

Gosselink, J.G. and Turner, R.E., 1978. The role of
wetland ecosystems. Freshwater Wetlands Ecological
Potential. New York: Academic Press, pp. 63-78.


Vol. 32,

hydrology in freshwater
Processes and Management

Hartman, B., 1978. Rare and Endangered Biota of Florida. Gainesville, Florida:
University Presses of Florida. Vol. 1, pp. xxvi-xxix.

Jacobs, J., 1975. Diversity, stability, and maturity in ecosystems
human activities. Unifying concepts in Ecology. The Hague:
Publishers, pp. 187-207.

influenced by
Dr. W.J.B.V.

Marth, D and Marth, M., 1985. The Florida Almanac, Gretna, Louisiana: Pelican
Publishing Co., Inc., 469 p.

Niering, W.A., 1985. Wetlands, New York: Alfred A. Knhpf, Inc., 640 p.


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