Citation
Gulf Coast Barrier Island Restoration: Public Demonstration and Education, Production Practices for the Beach Plant Iva Imbricata, and Restoration with Composite Plantings

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Title:
Gulf Coast Barrier Island Restoration: Public Demonstration and Education, Production Practices for the Beach Plant Iva Imbricata, and Restoration with Composite Plantings
Creator:
RAYMER, JOSIAH SHANE
Copyright Date:
2008

Subjects

Subjects / Keywords:
Dunes ( jstor )
Fertility rates ( jstor )
Fertilizer rates ( jstor )
Plant growth ( jstor )
Plant roots ( jstor )
Planting ( jstor )
Plants ( jstor )
Rooting ( jstor )
Sand ( jstor )
Species ( jstor )
Santa Rosa County ( local )

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Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
Copyright Josiah Shane Raymer. Permission granted to University of Florida to digitize and display this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Embargo Date:
7/24/2006
Resource Identifier:
496180319 ( OCLC )

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Full Text











GULF COAST BARRIER ISLAND RESTORATION:
PUBLIC DEMONSTRATION AND EDUCATION,
PRODUCTION PRACTICES FOR THE BEACH PLANT Iva imbricate,
AND RESTORATION WITH COMPOSITE PLANTINGS














By

JOSIAH SHANE RAYMER


A THESIS PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
MASTER OF SCIENCE

UNIVERSITY OF FLORIDA


2006
































Copyright 2006

by

Josiah Shane Raymer


































This document is dedicated to everyone who has helped me survive my college career.
















ACKNOWLEDGMENTS

I would like to thank all of the people who have helped me with my research. I

thank all of the teachers who have passed on their knowledge to me; I will try and put it

to good use. In particular I would like to thank Mack Thetford and Debbie Miller whose

guidance helped immensely in the creation of this thesis, Rick Schoellhorn for being a

friend, Peggy Olive for telling me learning is more important than good grades, and

lastly, I want to thank my friends who have helped me during the past several years and

supported me being a student.




















TABLE OF CONTENTS

Page


ACKNOWLEDGMENT S ................. ................. iv.............


LI ST OF T ABLE S ................. ................. vii........ ...


LIST OF FIGURES .............. ....................ix


AB STRAC T ................ .............. xii


CHAPTER


1 INTRODUCTION ................. ...............1.......... ......


2 DEMONSTRATION PLANTINGS AT NAVARRE BEACH (SANTA ROSA
ISLAND, FL)................ ...............3..


Percent of Responses ................... .... ......... ...............11......
Difference Between Pre and Post Program Responses ................... ....... ........... ........11
3 EFFECT OF FERTILITY RATE ON CUTTING PRODUCTION OF STOCK-
PLANTS OF Iva imbricata: ROOTING CHARACTERISTICS OF CUTTINGS
PRODUCED ................. ...............12.................


Introducti on ................. ...............12.................
Materials and Methods .............. ...............14....
Results and Discussion ................ ...............16........... ....

Experim ent One ............... ... ........... ....... ...............16...
Stock-plant growth and cutting production ................. ................ ...._.16
Rooting percentages and quality .............. ...............19....
Experiment Two ............... .. ... .....................2
Stock-plant growth and cutting production ................. ................. ...._20
Rooting percentages and quality .............. ...............21....
D discussion ................ ... ................... ............. ...... ........... .... ..................2
4 RESTORATION OF FOREDUNES WITH INTERMIXED COMPOSITE
PLANTINGS .............. ...............40....


Introducti on ................. ...............40.................

Study Site ................. ...............45.................
Methods .............. ... ...............46..

Experimental Design .............. ...............46....
Data Collection ................. ...............47.................













Analy si s ................. ...............47.......... .....
Re sults ................ ............ ...............48.......
Sand Accumulation .............. ...............48....
Survival ................. ...............49.................
Discussion ................. ...............49.................
Conclusions............... ..............5
APPENDIX


IVEANS AND STANDARD ERRORS FOR Iva imbricata PROPAGATION
STUDY ............. ...... ._ ...............58...


LIST OF REFERENCES ............. ...... .__ ...............68..


BIOGRAPHICAL SKETCH ............. ..............73.....
















LIST OF TABLES


Table pg

1 Results of preprogram and postprogram survey taken by ten coastal restoration
workshop participants. ................ ...............11.......... ......

2 Main effects by measured variable and experiment for total fresh weight cuttings,
number of cuttings produced, and fresh weight of individual cuttings. .................. .38

3 Main effects by measured variable and experiment for mean percent rooting, root
number, root length, and root index (root number root length). ...........................39

4 Incremental and total sand accumulation (cm) of height gained for 30 cm and 44
cm spacings of Iva imbricate, Panicum amarum, and Schizachyrium maritimum
planted in different combinations of 12 plants including a control (no plants).
Combinations consisting of two species have six plants of each species planted and
combinations consisting of three species have four plants of each species planted.
Iva = Iva imbricata, Pan = Panicum~PPP~~~~PPP~~~PPP ama~rum, Sch = Schizachyrium maritimum.
Analysis of variance for main effects and contrasts, significance at P < 0.05.........56

5 Mean survival (percent) for 30 cm and 44 cm spacings of Iva imbricata, Panicum
ama~rum, and Schizachyrium maritimum planted in different combinations of 12
plants. Combinations consisting of one species have 12 plants of the same species
planted and combinations consisting of two species have six plants of each species
planted. Combinations consisting of three species have four plants of each species
planted. Iva = Iva imbricata, Pan = Panicum~PPP~~~~PPP~~~PPP ama~rum, Sch = Schizachyrium
maritimum ............. ...............57.....

6 Iva imbricate stock-plants mean might (cm) and standard deviation of by harvest
and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-
2004). Fertilizer rate (fert) = fertility rates in (g) Osmocote/1 gallon container.
Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting.
Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting. ................... .58

7 Iva imbricate stock-plants mean width (cm) and standard deviation of by harvest
and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-
2004). Fertilizer rate (fert) = fertility rates in (g) Osmocote/1 gallon container.
Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting.
Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting. ................... .59










8 Iva imbricate stock-plants mean index (cm3) and standard deviation of by harvest
and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-
2004). Fertilizer rate (fert) = fertility rates in (g) Osmocote/1 gallon container.
Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting.
Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting...................60

9 Iva imbricate stock-plants mean total fresh weight (g) and standard deviation of by
harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc.
2000-2004). Fertilizer rate (fert) = fertility rates in (g) Osmocote/1 gallon
container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting.
Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting. ................... .61

10 Mean number and standard deviation of cuttings harvested from of Iva imbricate
stock-plants by harvest and fertility rate using repeated measures of proc mixed
(SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon
container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting.
Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting...................62

11 Mean cutting weight (g) and standard deviation of cuttings harvested from oflva
imbricata stock-plants by harvest and fertility rate using repeated measures of proc
mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon
container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting.
Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting. ................... .63

12 Mean root length (cm) and standard deviation of cuttings harvested from of Iva
imbricata stock-plants by harvest and fertility rate using repeated measures of proc
mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon
container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting.
Experiment 2, harvests 2-4 = 79, 108, and 136 days after potting. ................... .......64

13 Mean root number and standard deviation of cuttings harvested from oflva
imbricata stock-plants by harvest and fertility rate using repeated measures of proc
mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon
container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting.
Experiment 2, harvests 2-4 = 79, 108, and 136 days after potting. ................... .......65

14 Mean root index (cm) and standard deviation of cuttings harvested from of Iva
imbricata stock-plants by harvest and fertility rate using repeated measures of proc
mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon
container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting.
Experiment 2, harvests 2-4 = 79, 108, and 136 days after potting. ................... .......66

15 Mean rooting percentage and standard deviation of cuttings harvested from of Iva
imbricata stock-plants by harvest and fertility rate using repeated measures of proc
mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon
container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting.
Experiment 2, harvests 2-4 = 79, 108, and 136 days after potting. ................... .......67












LIST OF FIGURES


Figure pg

1 Preprogram and postprogram survey used to evaluate change in knowledge of
coastal restoration workshop participants. ............. ...............8.....

2 Backside of Beachgoers Guide to Sand Dunes trifold brochure created for
demonstration proj ect ................. ...............9............ ....

3 Frontside of Beachgoers Guide to Sand Dunes trifold brochure created for
demonstration proj ect ................. ...............10........... ....

4 Plant height by fertility rate, and month of harvest for Experiment One. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............27.....

5 Plant width by fertility rate, and month of harvest for Experiment One. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............27.....

6 Plant growth index ((mean width + ht)/2) by fertility rate, and month of harvest for
Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at
70oF) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. ................ ..................2

7 Total fresh weight cuttings by fertility rate and month of harvest for Experiment
One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per
one-gallon pot, 5.5, 11.0, 15.0, and 21.0. .............. ...............28....

8 Cutting number produced by fertility rate and month of harvest for Experiment
One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per
one-gallon pot, 5.5, 11.0, 15.0, and 21.0. .............. ...............29....

9 Cutting weight by fertility rate and month of harvest for Experiment One. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............29.....

10 Percent rooting by fertility rate, and month of harvest for Experiment One. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............30.....

11 Root number by fertility rate, and month of harvest for Experiment One. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............30.....










12 Root length by fertility rate, and month of harvest for Experiment One. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............31.....

13 Root index by fertility rate, and month of harvest for Experiment One. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............31.....

14 Plant height by fertility rate, and month of harvest for Experiment Two. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............32.....

15 Plant width by fertility rate, and month of harvest for Experiment Two. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............32.....

16 Plant growth index ((mean width + ht)/2) by fertility rate, and month of harvest for
Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at
70oF) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. ................ ..................3

17 Total fresh weight cuttings by fertility rate and month of harvest for Experiment
Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per
one-gallon pot, 5.5, 11.0, 15.0, and 21.0. .............. ...............33....

18 Cutting number produced by fertility rate and month of harvest for Experiment
Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per
one-gallon pot, 5.5, 11.0, 15.0, and 21.0. ............. ...............34.....

19 Cutting weight by fertility rate and month of harvest for Experiment Two. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............34.....

20 Percent rooting by fertility rate, and month of harvest for Experiment Two.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0. ............. ...............35.....

21 Root number by fertility rate, and month of harvest for Experiment Two. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............35.....

22 Root length by fertility rate, and month of harvest for Experiment Two. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............36.....

23 Root index by fertility rate, and month of harvest for Experiment Two. Fertility
rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-gallon pot,
5.5, 11.0, 15.0, and 21.0. ............. ...............36.....










24 Mean fresh weight of cuttings by run, fertility rate, and month of harvest. Expl1 =
Experiment 1, Exp2 = Experiment 2. Fertility rate in grams of Osmocote Plus (15-
9-12, 8-9 month @ 70 F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...................37

25 Map of Florida with insert showing the location of Santa Rosa Island. Arrows
indicate the location of the six study sites and Santa Rosa Sound. ................... .......55
















Abstract of Thesis Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Master of Science

GULF COAST BARRIER ISLAND RESTORATION:
PUBLIC DEMONSTRATION AND EDUCATION,
PRODUCTION PRACTICES FOR THE BEACH PLANT Iva imbricate,
AND RESTORATION WITH COMPOSITE PLANTINGS

By

Josiah Shane Raymer

May 2006

Chair: Deborah Miller
Major Department: Natural Resources and Environment

In order to promote plant diversity and increase wildlife habitat, residents,

contractors, and local officials need exposure to the benefits of using more than one plant

species for dune restoration. This was accomplished through a demonstration planting,

an educational kiosk, a brochure, and a website. Education of the public occurred when

materials were presented at a variety of meetings, workshops, and events. Workshop

participants were aware of the values of dunes but were less knowledgeable about

individual plants that grow in the coastal dune system. Ninety percent of the participants

gained some knowledge during the workshop. To investigate the effects of stock-plant

fertility on cutting production and rooting qualities oflva imbricata, stock-plants were

planted into one gal (3.8 L) containers. Plants were fertilized were fertilized with 5.5g,

11g, 15g, and 21g of Osmocote Plus (15N: 9P205: 12K20; 8-9 month formulation at

210C [700F], Scott Miracle-Grow, Marysville, OH 43041), applied as a topdressing, per










pot. Stock-plants were evaluated for shoot growth, total cutting production and rooting

characteristics. In Experiment One stock-plant height and width increased as fertility rate

increased for all harvests. The total fresh weight of cuttings and number of cuttings

produced increased linearly with an increase in fertilizer rate for all harvests. Rooting

response differed depending on the time of harvest. Percent rooting did not increase in

response to an increase in fertility rate for any harvest period. Fertility rate had an effect

on the number of roots per cutting that varied between harvests but did not influence root

length. In Experiment Two fertility rate had no effect on stock-plant height and mean

cutting weight, but stock-plant width and total fresh weight of cuttings increased as

fertility rate increased. Total fresh weight of cuttings and cutting number increased

linearly with an increase in fertilizer rate for all harvests. Increased fertility rate had a

negative to neutral effect on percent rooting and mean root number but did not affect root

length or cutting weight. High levels of fertility, which may be optimal for plant growth

and cutting production, may have a negative effect on rooting percentages, root number

and root length. Iva inabricata, Panicunt anzarunt, and Schizachyriunt naritinzun were

planted to examine the effect of intermixed composite plantings on transplant survival

and sand accumulation. All planting combinations accumulated sand at a rate greater

than bare sand controls. Intermixed composite plantings had a negative to neutral effect

on plant survival and sand accumulation when compared to monoculture plantings. Plant

density increased sand accumulation, however, survival of Schizachyriunt naritinzun

decreased as plant density increased.















CHAPTER 1
INTRODUCTION

Coastal dunes are found in almost all latitudes, but many are severely degraded by

the exploitation of natural resources, chaotic demographic expansion, and industrial

growth (Martinez and Psuty 2004). Coastal dunes exist in a dynamic environment often

impacted by tropical storms that erode the shoreline and destroy foredunes (Ehrenfeld

1990). Loss of foredunes can result in storm surge washing over the breadth of the island

damaging or destroying island ecosystems (Webb et al. 1997). Restoration of sand dunes

is important for the protection of barrier island infrastructure and ecosystems from the

further damaging effects of high tides, storm surges, and waves (Dahl et al. 1975). The

recovery of barrier island vegetation aids dune building, island stabilization, and provides

food and habitat for wildlife (Gore and Schaefer 1993, Snyder and Boss 2002, Swilling et

al. 1998).

The coastal dune ecosystem is complex and current restoration practices often do

not reestablish that complexity. Changing restoration practices for coastal dunes requires

public awareness and support. Garnering public support can be accomplished by

extending knowledge gained through research to the public. Through outreach the

importance of restoration of coastal dune systems can be conveyed and the need for

inclusion of restoration in any successful plan to conserve these coastal systems can be

supported.

Before the use of any plant in restoration can become wide spread, production must

be economical. Planting stock along with labor required for installation of plants










represents one of the maj or costs of dune restoration and can vary widely by species

(Woodhouse 1982). Plants suitable for wide use in restoration of coastal dunes must be

economical to produce (Woodhouse 1982). By developing more efficient production

practices for species such as Iva imbricate Walter [Asteraceae], planting stock costs can

be reduced, which in turn will increase Iva imbricate's suitability for wide use in

restoration proj ects.

Research into plant-plant interactions and the dynamics that control sand

movement and accumulation is key to development of effective restoration and

management techniques for dune ecosystems. We examined interactions between three

species of dune plants (Iva imbricata, Panicum ama~rum Ell. var. amarulum (A.S. Hitchc.

& Chase) P.G. Palmer, and Schizachyrium maritimum (Chapman) Nash [Poaceae]) and

the effect they have on sand movement and accumulation when planted on the beach.

This research will increase the information available on how to effectively restore and

manage coastal dune ecosystems.















CHAPTER 2
DEMONSTRATION PLANTINTGS AT NAVARRE BEACH
(SANTA ROSA ISLAND, FL)

In 1995, two maj or hurricanes impacted the Northwest Florida coast. Since these

storms, local home and condominium owners, county governments and contractors have

attempted dune restoration. However, government regulations designed to protect

endangered sea turtles, such as the Leatherback (Dermochelys coriacea (Vandelli), limit

or restrict the use of sand fence in the frontal dune position and create the need for

restoration with plantings and without sand fence.

Candidates for dune restoration include plants that are easily introduced, thrive in

blowing sand, trap sand well, and are relatively free of pests. Restoration projects often

rely heavily on Sea Oats (Uniola paniculata L. [Poaceae]) as it is the dominant grass of

foredunes in the southeast (Woodhouse 1982). Although there are other plants that make

substantial contributions to the geographical region, none are widely planted because they

fail to meet one of the above criteria (Woodhouse 1982). In order to promote plant

diversity and increase wildlife habitat, residents, contractors and local officials need

exposure to the benefits of using more than one plant species in dune restoration proj ects.

This is evident as 100% of calls to the Santa Rosa County extension office concerning

dune plantings involved customers wanting information on how to plant only Sea Oats

(personal communication C. Verlinde, September, 2003).

Gulf Bluestem (Schizachyrium maritimum (Chapman) Nash [Poaceae]), Bitter

Panic grass (Panicum ama~rum Ell. var. ama~rulum (A.S. Hitchc. & Chase) P.G. Palmer










[Gramineae]), Sea Oats (Uniola paniculata), and Beach Elder (Iva imbricate Walter

[Asteraceae]) are four western Gulf coast species commonly found in the frontal dune

zone of barrier islands (Craig 1991). Two of these four coastal species (Beach Elder and

Gulf Bluestem) have been the subj ect of propagation and production research and

protocol development. Developed protocols were published to facilitate increased

production of local populations of these coastal plants (Thetford and Miller 2004a, b).

Although interactions among these four coastal dune species are not well understood,

facilitation among plants in temperate and tropical dune systems has been documented

(Franks 2003a, b, Martinez 2003). Facilitation between species in composite plantings

may increase transplant survival and growth, rate of dune growth and diversity of plants

available for wildlife.

This proj ect was aimed at achieving two goals. The first goal was to increase

coastal awareness and stewardship. This was accomplished through an educational kiosk

at the demonstration planting site, a brochure, and a website. In addition, a traveling

program was developed for use at homeowner associations, civic organizations, planning

board meetings and coastal workshops. The program included samples of recommended

plants and a "how to" slide show. In addition, a survey was used at these meetings to

gage pre and post program knowledge about plant diversity in dune restoration (Figure

1). The second goal was to gather preliminary data (plant height, plant width, plant

survival) about dune plant interactions. Preliminary data was to be used to test and refine

planting methods for use in a full-scale experiment planted the following summer. This

data was not collected due to the loss of the plantings as a result of overwash from

hurricane Ivan (16, September 2004). The obj ective of the full-scale experiment was to









determine if composite plantings of Gulf Bluestem, Bitter Panic grass, Sea Oats and

Beach Elder might facilitate dune formation in a frontal dune zone in the absence of

fencing, and to examine the role facilitation and competition play in successful plant

establishment.

This proj ect was completed through a series of partnerships between WFREC

faculty, Santa Rosa County Sea Grant Extension Agent, Christina Verlinde, Escambia

County Sea Grant Extension Agent, Andrew Diller and Okaloosa County Sea Grant

Extension Agent, Scott Jackson M.S. graduate student Josiah Raymer and additional local

stakeholders. Stakeholders included: Gulf Islands National Seashore, Santa Rosa County

Board of County Commissioners, Navarre Beach Leaseholders Association, Santa Rosa

County 4-H1 Youth, and the Pensacola Bay Area Environmental Education Coordination

Team (with representatives from Florida Department of Environmental Protection, West

Florida Regional Planning Council, University of West Florida, Northwest Florida Water

Management District and additional civic and government organizations).

The physical portion of the proj ect (beach planting) was planted (17, May 2004)

with the help of University of Florida staff, the Santa Rosa County Extension Office, and

local 4-H1 volunteers. After which, deliverables for the project were developed.

Deliverables produced for this proj ect included a trifold brochure (Figures 2 and 3) and a

Power Point presentation that were utilized by the extension service to educate the public

about the proj ect and issues affecting the dune ecosystem. A poster presented in a kiosk

at the study site exposed beach visitors to the project and helped explain the purpose of

the demonstration plots. Dune restoration signs donated by Santa Rosa County were

placed at the demonstration site and a website containing all of the information about the










proj ect (pictures, plant information, trifold brochure, and power point presentation) was

made available for anyone wishing to learn more

(http://wfrec.ifas.ufl.edu/extension/dunes)

This proj ect aimed to educate the public about issues facing the dune ecosystem

and how these issues affect them. Education of the public occurred when materials were

presented at a variety of meetings, workshops, and events. These included 75 residents at

two Navarre Beach Leaseholders Association meetings where the proj ect was discussed

and brochures were distributed. Additionally the project was presented to 15 participants

of a Coastal Restoration Workshop where pre and post program surveys were completed

by each participant. A poster was presented and brochures were distributed at several

events including, Earthday at the Zoo April 2005 (100 people), Seagrass Awareness

Festival March 2005 (200 people), and the Coastal Encounters event Oct. 2005 (300

people). Brochures were also distributed through a local eco-tourism business on the

beach.

The long-term impact of this proj ect will be an increased awareness of some of the

issues affecting barrier islands. Measurable impacts of the program were evident from

the results of the pre- and post program tests administered at the Coastal Restoration

Workshop. Among the 15 participants, 10 completed both pre- and post program tests.

Results of the pretest indicated 100 percent of the participants were aware that dunes

provide habitat for animals, protect the mainland from storms, and naturally undergo

change (Table 1). The pretest also indicated that 100 percent of participants were aware

that dunes are formed by sand that is trapped by plants. This high level of knowledge

suggests many of the participants were highly knowledgeable about stewardship and the









function sand dunes play in the coastal dune ecosystem (questions 1 and 2). Eighty

percent of the participants also understood the concept of a monoculture suggesting that

the participants were somewhat knowledgeable about concepts pertaining to plant

diversity (question 3). This percentage did not increase in the post test and indicates that

understanding of the concept of monoculture was not increased by the workshop. Only

30 percent of the participants knew about the basic flowering characteristics for Beach

Elder prior to the workshop, and 60 percent knew about the basic flowering

characteristics of Gulf Bluestem indicating that participants were less knowledgeable

about individual plants that grow in the coastal dune system (questions 4 and 5).

Knowledge about individual plants was increased by the workshop and was reflected in

the increase in correct answers during the post test, which rose to 80 percent for Beach

Elder and 70 percent for Gulf Bluestem. When post program test scores were compared

to the pre program test scores there was a 16% difference in test scores. Ninety percent

of the participants gained some knowledge during the workshop. An additional impact of

this work was an increase in calls to the extension office asking where to get the plants

described in the brochure and on the web site and how to volunteer for dune restoration

projects. (personal communication C. Verlinde, October 2005).

On September 19, 2004 Hurricane Ivan came ashore on Santa Rosa Island and

destroyed the physical portion of the proj ect (demonstration plantings and kiosks). The

pamphlets, presentations, and website are still available and at this point there are plans to

replant the study on Navarre Beach once renourishment efforts are completed.












IFAS EXTENdSION Rodda

Please take a moment to fill out this survey before and after the Dune Restoration
Presentation. The information will be used to determine whether we are meeting the goals
of this program. Thanks in advance!!!!! i
Please circle your answers.
1. Why are dunes important?

A. Provide habitat for birds, reptiles and mammals
B. Protect the mainland and coastal development from storms
C. Part of a natural changing environment of a barrier island
D. All of the above

2. Dunes are formed when:

A. It rains
B. Mice live near them
C. Sand is trapped among plants leaves, stems and roots
D. When a sea turtle nests

3. A monoculture is:

A. A single grain of sand
B. Where only 1 species of plant is utilized (sea oat turf)
C. An exotic plant
D. None of the above

4. Which dune plant has small lavender flowers that occur in late summer?

A. Gulfbluestem
B. Bitter panicum
C. Sea oats
D. Beach elder

5. The seed head of this plant has dense silvery hairs.

A. Bitter panicum
B. Sea oats
C. Gulf bluestem
D. Beach elder
Name

Figure 1. Preprogram and postprogram survey used to evaluate change in knowledge of
coastal restoration workshop participants.












Would you Mse~ to learn more?
Your Florida Sea Grant agent is available
for an on-site presentation to your school
or homeowners organization


: Ga.UuNIVERSITYU OF
.~1 FLORIDA
SCHOOL OF
NATURAL RESOURCES
AN\D ENVIRONMENT


How to Carce
...and Whyl


Figure 2. Backside of Beachgoers Guide to Sand Dunes trifold brochure created for
demonstration project.


res adship of the dune system. For more information:
members assisted virig online:
atduate~ http //wireCniasFuf edulextensionidunes
Josiah Raymer
with planting- or call:
Christina Verlinde
UF/IFAS Flonda Sea Grant
(850) 623-3868


~1
B~~!t" %





























Beach elder(Iva imbricata) has sparse How are dunes formed? Gulf bluestem (Schiracilvrium
woody,upnghtstesandfleshynarrowright Coastal dunesare fomed whmnsand is trapped ncmanritmn)is acreeping, peremlialgrassesily
green leaves. Smaml lavender flowers occur in around the stems, leaves and roots of plants in identified by silvery blue leaves. Ihe seed
late sumrmer Beach elder accumulates sand the vegetated areas of the beack heads, wlnchmature inlate summer are
rapidly and produces low rounded dunes distinguished by dense silvery hairs.
Why are dunes Important?
The sand dune system along Flnida beaches
helps protect themainland and buildings from
the farce oftropical simms and hmricanes.The


10





Do you knowr yeu ~i
Plants used in this restoration project occurr natmally along coastal dimes throughout the Gulf COast. Dune plants are adaptedio the harsh edansm
of the beach such as temperature extremes, saltwater spray and soil (mostly sand) that is low in nutient and moisture. Plants in ihe dune system
trap sand, which stabilizes dunes and promotes dune founation For sure information on the plants used in this pE ed C etk Owt.
http:Uwnfree ifas ufl edulextenstoodunes or visit the project sites onNav-ane Beach at Public Access #7, 8, 10, and 11.


dunesysamalrarbstle ergy ofstannwave.

Why use differnt plants
to restore dunesT
Alang the Gulfaf~exmpmadiffacut~
npnaturly ocernt ~n thedn

spenesoffer`
and thu more opportunitiesifer
4 By imiaitin this richesrsin;~speaes, dues a n mA -t~~i
be reslered iltma t way a thatmayl alo plkeswinch acnet m arlfal
benefitanstual Epes that usethe dunes fepr h~~eads hkile &eoa~


Batter panicum(Panicionamarum)
is a tall clumpamg, per~nnial grass with large,
wide, siver/ble leaves. Thle upright groth
Mtn~il-hAMA~w ourt when compaed o other


Figure 3. Frontside of Beachgoers Guide to Sand Dunes trifold brochure created for
demonstration project.









Table 1. Results of preprogram and postprogram survey taken by ten coastal restoration
workshop participants.

% of responses Difference Between
Pre and Post
Question Response Preprogram Postprogram Program Responses
1 A 100 100 0
B 0 0 0
C 0 0 0
D 0 0 0

2 A 0 0 0
B 0 0 0
C 100 100 0
D 0 0 0

3 A 0 0 0
B 80 80 0
C 0 10 10
D 20 10 -10

4 A 30 0 -30
B 10 20 10
C 0 0 0
D 30 80 50

5 A 20 20 0
B 0 10 10
C 60 70 10
D 0 0 0















CHAPTER 3
EFFECT OF FERTILITY RATE ON CUTTING PRODUCTION OF
STOCK-PLANTS OF IVA IMBRICATA:
ROOTING CHARACTERISTICS OF CUTTINGS PRODUCED

Introduction

Seacoast Marshelder (lva imbricata Walter [Asteraceae]) (hereafter referred to as

Iva) is a dominant seashore plant and occurs on coastal dunes throughout the south

Atlantic and Gulf region. Iva can spread vegetatively and by seed and is the only broad-

leaved plant with a potential for building and stabilizing foredunes in the South Atlantic

coast of the United States (Woodhouse 1982). Iva can grow throughout primary and

most secondary successional zones and is occasionally found alone building foredunes

but is usually found in combination with one or more dune grasses (Woodhouse 1982).

Iva is used for dune restoration and stabilization proj ects (Craig 1991) and has also been

identified as an important food for beach mice (Moyers 1996).

Iva is a perennial C3 shrub (Franks 2003), which produces inflorescences at the tips

of its stems in the fall. Iva has sparse woody stems from one to four feet (30 to 122 cm)

tall with fleshy, narrow, lance shaped leaves. Highest rates of seed production on mature

plants occur in foredunes while successful seedling establishment occurs in areas of little

sand movement and favorable moisture (Woodhouse 1982) causing highest germination

rates to occur on open beach or upper marsh in the spring (Colosi and McCormick 1978).

Iva develops a strong system of rhizomes and roots when buried by soil and produces

gently rounded dunes (Craig 1991). These growth characteristics make Iva desirable for

dune restoration but the timing of seed production in natural regeneration may not










provide sufficient plants for restoration and warrants development of efficient

propagation and production practices for restoration efforts.

Softwood cuttings of Iva stems root readily (Craig 1991) with rooting percentages

greater than 90% achievable with or without auxin application for ten cm cuttings

collected from native populations (Thetford and Miller 2002). Management of stock-

plants in a nursery setting is desirable for producing a reliable and consistent source of

cuttings. However, it is not presently known if container production of stock-plants for

this purpose is a viable alternative or if stock-plant fertility may have an affect on cutting

production, rooting percentage or the quantity or quality of the roots produced. Stock-

plant nutritional fertility has been shown to be a factor in the rooting of softwood and

hardwood cuttings (Blazich 1988, Veierskov 1988). For example cuttings of

Pelargonium sp (Geranium) harvested from stock-plants grown under low and medium

fertility rates (N, P, K) demonstrated an increase in rooting percentage when compared to

high fertility rates (Haun and Cornell 1951, Blazich 1988, Veierskov 1988). A similar

response was noted by Preston et al. (1953) when propagating Rhododendron sp.

(Azalea) maintained under similar fertility rates where low and medium rates

demonstrated higher rooting percentages than high fertility rates. Optimum stock-plant

nitrogen levels for rooting of cuttings has also been shown to occur below the optimum

level for stock-plant growth for Juniperus virginiana L. (Eastern Red Cedar) where

optimum growth occurred at 100-150 mg/L N while optimum rooting occurred at 20-40

mg/L N (Henry et al. 1992). This previous work demonstrates a need to consider not

only the effects of fertilization on the number of cuttings produced, but to also consider

the effects of stock-plant fertility on the rooting success of cuttings when optimizing









stock-plant fertility rates. Finding an acceptable level of stock-plant fertility to maximize

cutting production without sacrificing root quality will lead to better management

practices. The obj ective of the following experiments was to investigate the affects of

stock-plant fertility on cutting production and evaluate the rooting qualities of harvested

cuttmngs.

Materials and Methods

Forty-eight stock-plants of Iva were planted on both 3 February, 2004 (Experiment

One) and 9 July, 2004 (Experiment Two) using eight cm liners transplanted into one gal.

(3.8 L) containers. Liners were grown in a pine bark substrate amended with six lbs. (2.7

kg) dolomitic limestone per yd3 (0.76 m3). Plants were pruned to eight cm in height

seven days after planting (DAP).

Osmocote Plus (15N: 9P205: 12K20; 8-9 month formulation at 210C [700F], Scott

Miracle-Grow, Marysville, OH 43041) was applied as a top dressing at 5.5 g, 11 g, 15 g,

and 21 g per pot with 11 g representing the recommended fertility rate for a one gallon

plant. Plants were grown in full sun receiving 30 min of overhead irrigation twice daily.

The experiment was a completely randomized design consisting of four fertility

treatments with 12 single-plant replications.

Experiment One was initiated using dormant liners while Experiment Two was

initiated during the growing season. First harvest was conducted when all of the stock-

plants in the experiment had sufficient growth to collect at least four 10 cm cuttings. The

first harvest of cuttings from each experiment began 114 and 49 DAP respectively.

Stock-plants were evaluated for shoot growth (stock-plant height and width) and total

cutting production at each of 4 harvest dates [1 14,146, 175, and 206 DAP for Experiment

One and 49, 79, 108, and 136 DAP for Experiment Two.]. Each plant was measured for









maximum shoot height and width (mean of two perpendicular widths) and all tip cuttings

10 cm in length harvested. The total number and total weight (g) of cuttings collected

from each plant was recorded and the stock-plants were cut back to a height of 20 cm.

Rooting characteristics of cuttings were quantified utilizing a sub-sample of four

cuttings randomly selected from the pool of cuttings taken from each stock-plant at each

harvest. Cutting were stripped of leaves two cm above the base and a fresh cut made

prior to treatment with Hormodin-1, 1000 mg/L IBA (indole-3-butyric acid) auxin

rooting powder (OHP, Inc., Mainland, PA 19451). Each rooting experiment contained

four cuttings from each of the 12 stock-plants representing each of the four fertilizer

treatments for a total of 192 cuttings. However, the first harvest of Experiment Two did

not yield sufficient cuttings so no rooting data are available for that date. All rooting

experiments were arranged in a randomized complete block design with each of the 12

blocks containing 16 cuttings. Bench position was used as a blocking factor to account

for differences in environmental conditions along the length of the greenhouse bench.

Cuttings were inserted two cm deep into 72 cell plug flats filled with Fafard #4M

Mix (40% peat, 35% vermiculite, 25% bark) (Conrad Fafard, Inc., Agawam, MA 01001).

Cuttings were randomly placed under intermittent mist operating at four seconds of mist

every ten min from 7:00 A.M. to 8:00 P.M. with bottom heat of 800F.

Cuttings were evaluated for rooting 14 days after sticking and the roots washed free

of propagation substrate. Root number (primary roots emerging from the cutting) and

length of the longest root (cm) were recorded for each cutting.

Mean fresh weight of cuttings was calculated for each stock-plant using total fresh

weight of all cuttings harvested divided by total number of cuttings harvested. A plant










growth index was calculated for each stock-plant using plant height and width ((mean

width + ht)/2) to evaluate the combined effects of changes in height and width and

monitor overall changes in plant growth form. Rooting percentage was calculated based

on the number of cuttings rooted from each stock-plant. An estimate of total root length

was calculated as the product of root number and root length to estimate the combined

effects of root number and root length.

Data were analyzed for treatment affects using the general linear models procedure

of SAS (SAS Institute Inc. 2000-2004).

Results and Discussion

Stock-plant growth and cutting production were influenced by the rate of fertilizer

applied but responses were not consistent across harvest times or between the two

experiments. This trend was also true for rooting percentage and measures of root

quality. The two experiments had differing responses, which were thought to be a result

of seasonal growth effects associated with the timing of the two experiments. Hence, data

for the two experiments are presented separately.

Experiment One

Stock-plant growth and cutting production

The main effects of fertility and harvest both had a significant effect on stock-plant

size as shown by changes in height, width and growth index (Table 1). There were

significant interactions between the effects of fertility and harvest for all variables except

stock-plant width. Pearson correlation coefficients indicate stock-plant height and width

were not correlated although both were highly correlated with growth index (r = 0.858

and 0.816 respectively).









Stock-plant height increased as fertility rate increased for all harvests (Figure 1).

There was a significant decrease in stock-plant height for all harvest periods when

fertility rate decreased to 5.5 g, a rate representing half the recommended rate of 11 g.

Prior to the first harvest of cuttings plant height followed a classic fertilizer growth

response curve and maximum height was achieved between the rates of 11 g and 15 g.

However, after first harvest plant height did not differ between the 11 g, 15 g, and 21 g

fertilizer rate.

Stock-plant width increased as fertility rate increased for all harvests (Figure 2).

There was a significant decrease in stock-plant width for all harvest periods when fertility

rate decreased to 5.5 g. Plant width did not differ between the 11 g and 15 g, however,

and there was a significant increase in plant width when the fertility rate was increased to

the 2-times recommended rate of 21 g when compared to the recommended rate.

Fertilizer rate had a significant effect on stock-plant growth index resulting in an

increase in plant growth index as fertilizer rate increased (Figure 3). This response was

particularly evident prior to the first harvest of cuttings when the greatest differences in

stock-plant size were evident and followed a classic quadratic fertilizer growth response

curve (Figure 3). When fertilizer was applied at half the recommended rate of 11 g there

was a 35% decrease in plant growth index while fertilizer applied at twice the

recommended rate of 11 g resulted in a 13% increase in plant growth index. After the

initial harvest of cuttings plant growth index did not differ among plants fertilized with

11 and 15 g of Osmocote. The data suggests nearly a 2x application of the recommended

rate is necessary to affect a significant increase in plant growth index for Iva stock-plants.









Although hedging of stock-plants reduced height to 20 cm following each

successive harvest of cuttings, stock-plant growth index (Figure 1) increased with each

successive harvest (P < 0.0001). The effects of increasing stock-plant width resulted in a

5% increase in growth index from harvest one to the harvest four.

Fertility rate as well as time of harvest had a significant effect on the total fresh

weight of cuttings removed from each plant (P < 0.0001, Table 2). The total fresh weight

of cuttings increased linearly with an increase in fertilizer rate for all harvests (Figure 4).

Total fresh weight of cuttings decreased 35% from harvest one to harvest three before

increasing 27% from harvest three to harvest four for the 11 g rate.

Fertility rate had a significant effect on cutting number (P < 0.0001). The number

of cuttings produced per stock-plant increased linearly with increasing rate of fertility for

all harvests (Figure 5). The number of cuttings produced at the recommended rate per

stock-plant increased with each successive harvest (P < 0.0001), resulting in an increase

of 93% from harvest one to harvest four (Figure 5). Pearson correlation coefficients

indicate that the number of cuttings produced was not correlated with plant height (r =

0.2539) or index (r = 0.5733) but was highly correlated with plant width (r = 0.74923)

across harvests. This suggests stock-plant width has a greater positive effect on increases

in cutting production than stock-plant height and that managing stock-plants in a fashion

that increases width will result in an increase in cutting production.

Fertility rate as well as time of harvest had a significant effect on individual cutting

weight (P < 0.0001). The weight of individual cuttings increased linearly with an

increase in fertilizer rate for harvests one and two (Figure 5). Cutting weight was 53-

56% greater at harvest one than at other harvests when averaged across fertility rates









(Figure 6). At the time of the first and second harvests, cutting weight increased 24% and

10% with a doubling of the fertility while cutting weight did not differ at 2x the

recommended rate at the third and fourth harvests.

Rooting percentages and quality

The main effects of fertility and time of harvest were significant for most measured

rooting variables (Table 3). An interaction was present between the main effects of

fertility and time of harvest for all measured variables indicating the rooting response

differed depending on the time of harvest.

Percent rooting was influenced by fertility rate (P = 0.003 5) and the time of harvest

(P < 0.0001) (Figure 7). Percent rooting did not increase in response to an increase in

fertility rate for any harvest period. Harvests one and four had rooting percentages

between 88% and 100% for all fertility levels. Rooting percentages for harvest period

two declined linearly as fertility level increased and ranged from 79% at the lowest rate

to 54% at the highest rate. Rooting percentages for harvest period three declined linearly

as fertility level increased and ranged from 63% at the lowest rate to 35% for the highest

rate. Increasing fertility rate ofl. imbricata stock-plants does not increase the rooting

percentage of harvested cuttings.

Fertility rate had a significant effect on the number of roots per cutting (P = 0.016)

but did not influence root length (P = 0.0772) (Figures 8 and 9). During harvest period

one root number declined linearly as fertility rate increased and ranged from 8.6 roots per

cutting at the lowest rate to 6.3 roots per cutting at the highest rate. Root number did not

differ in response to fertility rate for harvests two through four with 4.3 to 6.9 roots

produced per cutting.









Fertility rate as well as time of harvest had a significant effect on root index (P =

0.0151 and P < 0.0001)(Table 3). Root index decreased linearly as fertility rate increased

for harvest one (Figure 10). Root index then began to increase linearly as fertility rate

increased for harvest four.

Experiment Two

Stock-plant growth and cutting production

The main effects of fertility and time of harvest both had a significant effect on

stock-plant width and growth index but did not have a significant effect on stock-plant

height (Table 1). There were no significant interactions between the effects of fertility

and harvest for height, width or growth index (Table 1). Pearson correlation coefficients

indicate stock-plant height and width were not correlated although width was highly

correlated with growth index (r = 0.7803).

Fertility rate had no effect on stock-plant height (Figure 11) but decreases in stock-

plant height following each harvest of cuttings indicate plant regrowth was affected by

the time of harvest (P < 0.0001). Stock-plant fertility did have a significant effect (P <

0.0001) on stock-plant width (Figure 12). Compared to the standard rate of 11 g, there

was a significant decrease in stock-plant width for all harvest periods when fertility rate

decreased to 5.5 g. Stock-plant width at the 5.5 g rate of fertilizer remained nearly

constant following each successive harvest of cuttings. Stock-plant width increased with

each subsequent harvest of cuttings when fertilizer was applied at the recommended rate

or greater. However, stock-plant width did not differ among plants fertilized at 11 g, 15 g,

or 21 g rates.

Fertility rate (P < 0.0001) and time of harvest (P =0.0004) both had a significant

effect on plant growth index. Plant growth index demonstrated a linear or quadratic









increase as fertilizer rate increased. The greatest increase in plant index occurred from

5.5 g to 11 g and no significant increase in plant index was evident when the fertilizer

rate was doubled to 21 g. (Figure 13). The data suggest that even a 2x fertility rate does

not increase stock-plant growth index compared to the recommended rate.

Fertility rate as well as time of harvest had a significant effect on the total fresh

weight of cuttings removed from each plant (P < 0.0001)(Table 2). The total fresh

weight of cuttings increased linearly with an increase in fertilizer rate for all harvests

(Figure 14). Total fresh weight of cuttings increased 178% from harvest one to harvest

four for the 11 g rate. Total fresh weight of cuttings decreased 23% from harvest two to

harvest three causing an interaction between fertilizer rate and harvest period.

Fertility rate (P < 0.0001) had a significant effect on the number of cuttings

harvested. Cutting number increased linearly as fertility rate increased (Figure 15).

Reducing the fertilizer rate to 5.5 g resulted in a 29% to 48% decrease in cutting

production. However, increasing the fertilizer rate above 11 g did not increase the

number of cuttings produced per plant. Cutting number also differed with the time of

harvest (P < 0.0001). Cutting number began to increase by the third harvest of cuttings

and then began to decrease at the fourth harvest. Fertility rate did not have a significant

effect on mean cutting weight (P = 0.3750) but cutting weight did increase from harvest

one to harvest four (P < 0.0001)(Figure 16).

Rooting percentages and quality

The main effects of fertility and time of harvest were significant for most rooting

variables (Table 3). An interaction was also present between the main effects of fertility

and harvest for all rooting variables indicating the rooting response differed depending on

the time of harvest.









Percent rooting was influenced by fertility rate (P = 0.0269) and the time of harvest

(P < 0.0001) (Figure 17). Rooting percentages for cuttings collected during harvest two

remained above 90% regardless of the level of stock-plant fertility. However, at

subsequent harvests, rooting percentages began to decrease for cuttings taken from plants

receiving less that 21 g of fertilizer. At harvest three rooting percentages indicate a linear

increase as the rate of stock-plant fertility increased resulting in a 28% decrease in

rooting percentage from the 21 g rate to the 5.5 g rate. Rooting percentages further

decreased as fertility rate decreased at harvest four and ranged from 64% to 83%.

Both fertility rate (P = 0.0059) and time of harvest (P < 0.0001) had a significant

effect on mean root number (Table 3). At harvest two the number of roots per cutting

initially increased as stock-plant fertilizer rate increased but this trend became reversed

by the fourth harvest (Figure 18). The number of roots per cutting for harvest period two

was 21% to 63% higher than root number for subsequent harvests. Root number per

cutting decreased through harvest period four and cuttings from stock-plants fertilized at

11 g had 5.2 roots per cutting by harvest four.

Mean root length was not affected by the rate of stock-plant fertilizer treatment (P

= 0.2079), however root length did differ with the time of harvest (P < 0.0001). Root

length was significantly higher during harvest two compared to subsequent harvests

(Figure 19). Root length decreased from 10 to 12 roots per cutting at harvests two to only

two roots per cutting at harvest four. The similar decreases in root number and root

length are also reflected in the root index (Figure 20). The effects of stock-plant fertility

and time of cutting harvest on root index resembles the response of root number more

than root length.









Fertility rate as well as time of harvest had a significant effect on root index (P =

0.0008 and P < .0001)(Table 3). Root index increased linearly as fertility rate increased

for harvest two but had no effect for harvests three and four (Figure 20). Root index was

286% to 913% higher at harvest two than at harvests three and four showing a dramatic

reduction in root index from period two to four.

Discussion

The effect of fertility rate on plant growth before the first harvest of cuttings from

both Experiments one and two exhibited a classic growth response curve in response to

an increase in fertilizer rate (Figures 3 and 13). In both experiments, the greatest increase

in growth occurred when the rate of Osmocote increased from the 5.5 g to 11 g. The rate

of growth slowed but continued to show an increase when the rate of Osmocote increased

from 11 g to 15 g. Iva growth rate did not increase when the rate of Osmocote was

increased from 15 g to 21 g. This trend was exhibited for both plant height and plant

width (Figures 1, 2, 11, and 12). These results indicate the growth rate of Iva can be

increased with the application of Osmocote up to the 15 g rate but no additional benefit in

growth can be achieved with further increases in the rate of fertilization. Maximizing

plant growth with the application of 11 to 15 g of Osmocote will allow for shorter grow

out times in a nursery production system, which will in turn increase the numbers of

plants that can be produced in a given time period while reducing production costs.

After the first harvest of cuttings for both experiments, increases in plant height in

response to fertilizer slowed while plant width continued to increase in response to an

increase in fertility rate. In addition, width also increased with each successive harvest

and was highly correlated with an increase in the number of cuttings produced. Cutting

production has also been shown to increase with successive harvests in Antirrhinum,










Chrysocephalum, Dia~scia, Lavendula, Osteospermum, and Verbena in response to

hedging. This shows that hedging stock-plants results in an increase in cutting number

(Faust and Grimes 2005). Faust and Grimes (2005) also found that increasing the hedging

height in successive harvests maximized cutting production. Iva stock-plants were

hedged to a constant height in our experiments but further increases in the number of

cuttings produced may have been realized with successive increases in stock-plant height

following each successive harvest. Over a 23 week period cutting quantity and quality of

Scaevola cuttings has been shown to increase over time as N fertilization concentration

increased from 100 to 300 mg/L (Gibson 2003). Similarly, stock-plants ofPelargonium

sp. have been shown to produce low numbers of cuttings at a 50 mg/L rate while

producing higher numbers of cuttings at the 100 mg/L, 200 mg/L, and 400 mg/L rates

(Ganmore-Neuman and Hagiladi 1990, 1992).

The strong correlation in Experiment One and weak correlation in Experiment Two

between the increase in stock-plant width and the increase in cutting production suggests

that managing stock-plants in a manner that increases width will also cause cutting

production to increase as fertility level increases. But, similar to plant growth, cutting

number did not continue to increase as fertilizer rates were increased above the 15.0 g

rate.

Time of harvest had a stronger influence on the weight of individual cuttings than

did the rater of fertilizer. When cutting weight is graphed across time (Figure 21) the

lowest weights per cutting were evident during the months of June and July and

correspond with the period of lowest rooting percentages. Seasonal effects on cutting

production and quality have been reported for many crops such as Pelargonium sp. and









Cotinus coggygria (Ganmore-Neuman and Hagiladi 1992, Cameron et al. 2005). Work

by (Ganmore-Neumann et al. 1992), showed that low irradiance levels during stock-plant

growth caused a drop in cutting production while causing an increase in rooting

characteristics. Cameron et al. (2005) showed that rooting percentages responded to

changes in photoperiod differently according to season. Rooting of cuttings harvested in

August were unaffected by short day compared to long day photoperiod while cuttings

harvested in September had higher levels of rooting in the long day photoperiod.

Changes in light characteristics may have been a factor in the seasonal effect on rooting

percentages of cuttings taken from Iva stock-plants.

Stock-plant nutrition has been shown to have a significant effect on rooting

percentages (Blazich 1988, Veierskov 1988), as was observed in this study. Rooting

percentage had an inverse relationship with fertility rate from May through July

suggesting that high levels of fertility should be avoided during that period to keep from

negatively affecting rooting percentages. High levels of fertility, which may be optimal

for plant growth and cutting production, had a negative affect on rooting percentages,

root number and root length. This inverse relationship has also been demonstrated in

cuttings taken from stock-plants of Pelargonium sp, Rhododendron sp, and Eastern

Redcedar (Haun and Cornell 1951, Preston et al. 1953, Henry et al. 1992). Haun et al

(1951), Preston et al (1953), and Henry et al (1992) all found inverse relationships

between stock-plant fertilization and rooting percentages in cuttings harvested from

stock-plants. With lva this trend was not consistent throughout the season. Higher

fertilizer rates had a neutral to positive effect on Iva rooting percentage and quality









during the months of August through November. This may be a result of the onset of

flowering in Iva, which is fall flowering, or the onset of dormancy.

The recommended rate of 1 1.0 g of Osmocote Plus per one-gallon pot produced

nearly maximum plant growth and resulted in acceptable rooting percentages throughout

the growing season. Optimum rooting percentages occurred from May to early June and

August through September, suggesting two optimum harvest periods. Utilizing a stock-

plant hedging technique was a successful method for the production of Iva cuttings.

Propagators should prune stock-plants to maximize plant width during spring and

schedule a harvest of cuttings from May to early June. After this initial harvest of

cuttings stock-plants may benefit from a period of growth when rooting percentages are

minimal. By scheduling a second harvest during August through September, cutting

production will be maximized and cuttings will be propagated at a time when cuttings

root at a high percentage. Avoiding harvest and propagation of cuttings when rooting

percentages will be at their lowest will improve propagation success and increase

production efficiency.
















-


451

40 -

E
0 35


*930
I
25 -

20


-+- harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


10 15 20 25


30


25


.c 20


15


10


-* Harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


0 5 10 15 20 25
Fe rtility Rate (g)

Figure 5. Plant width by fertility rate, and month of harvest for Experiment One.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.


Fertility Rate (g)

Figure 4. Plant height by fertility rate, and month of harvest for Experiment One.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.



















































0 5 10 15 20 25


35


30

x
$ 25


-+- harvest 1
-a Harvest 2
-A- Harvest 3
- Harvest 4


15 20 25


Fe rti lity Rate (g)


Figure 6. Plant growth index ((mean width + ht)/2) by fertility rate, and month of harvest
for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9
month at 70oF) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.


-* Harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


Fertility Rate (g)

Figure 7. Total fresh weight cuttings by fertility rate and month of harvest for
Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9
month at 70oF) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.



























0 5 10 15 20 25


S20



10


-* Harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


Fertility Rate (g)

Figure 8. Cutting number produced by fertility rate and month of harvest for Experiment
One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF)
per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.


En2.0

En1.5

O 1.0

0.5


-* Harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


0 5


10 15 20 25


Fe rtility Rate (g)

Figure 9. Cutting weight by fertility rate and month of harvest for Experiment One.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.












100

90

80

70 5

60

50 a

40

30


5 10 15 20 25


-* Harvest 1
-t Harvest 2
+- Harvest 3
--Harvest 4


0 5 10 15 20 25
Fertility Rate (g)

Figure 10. Percent rooting by fertility rate, and month of harvest for Experiment One.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.


16

14

12

S10

o 8

S6

4

2


-*- harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


Fertility Rate (g)

Figure 11. Root number by fertility rate, and month of harvest for Experiment One.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.



















O 1 -----
I


-*- harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


10 15 20 25


.. -




5 10 15 20 25


-* Harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


Fertility Rate (g)


Figure 12. Root length by fertility rate, and month of harvest for Experiment One.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.


Fertility Rate (g)


Figure 13. Root index by fertility rate, and month of harvest for Experiment One.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.


























5 10 15 20 25


~c~c~--


45

40


0 35

30

25

20


-*- harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


30


25


.c 20


15


10


-+ Harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


0 5 10 15 20 25
Fe rtility Rate (g)

Figure 15. Plant width by fertility rate, and month of harvest for Experiment Two.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.


Fertility Rate (g)


Figure 14. Plant height by fertility rate, and month of harvest for Experiment Two.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.











































... .......-----


30


S25


S20


15


-+- harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


...--A


Figure 16. Plant growth index ((mean width + ht)/2) by fertility rate, and month of
harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-
12, 8-9 month at 70oF) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.


20


S15


S10

S5
L.

O


-* Harvest 1


10 15 20 25


Fertility Rate (g)


Fertility Rate (g)

Figure 17. Total fresh weight cuttings by fertility rate and month of harvest for
Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9
month at 70oF) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.


























5 10 15 20 25


0 5 10 15 20 25


35

30

t 25

S20



10

5

0


-* Harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


3.0

2.5
-
Qe 2.0

S1.5

ca1.0


-* Harvest 1
-m Harvest 2
-A- Harvest 3
- Harvest 4


C~c~


Fe rtility Rate (g)

Figure 18. Cutting number produced by fertility rate and month of harvest for
Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9
month at 70oF) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.


F e r i i y R t g

Figure 19. Cutting weight by fertility rate and month of harvest for Experiment Two.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.













ii
k

k
k


Figure 20. Percent rooting by fertility rate, and month of harvest for Experiment Two.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.


16

14

12

# 10 1 Harvest 2
o I +- Harvest 3
8
--Harvest 4
6'


-tHarvest 2
- Harvest 3
--Harvest 4


Figure 21. Root number by fertility rate, and month of harvest for Experiment Two.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.


Fe rtility Rate (g)


Fe rtility Rate (g)
















Y



t-----~t


200
180 '-
160
140
120
100
80
60
40
20
0


+ Harvest 2
+- Harvest 3
--Harvest 4


2-1


10 15 20 25


SHarvest 2
+- Harvest 3
--Harvest 4


0 5 10 15 20 25
Fe rtility Rate (g)

Figure 23. Root index by fertility rate, and month of harvest for Experiment Two.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.


Fe rtility Rate (g)

Figure 22. Root length by fertility rate, and month of harvest for Experiment Two.
Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70oF) per one-
gallon pot, 5.5, 11.0, 15.0, and 21.0.









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CHAPTER 4
RESTORATION OF FOREDUNES WITH INTERMIXED COMPOSITE PLANTINGS

Introduction

Tropical cyclones can cause extensive damage to coastal ecosystems. Foredunes,

the primary barrier to the damaging effects of storm surge on inland areas, absorb the

brunt of these storms. Storm surge and attending waves often result in partial to complete

destruction of foredunes creating a need for dune restoration.

Dune restoration projects along the Southeast coast of the United States often plant

monocultures of Uniola paniculata L. [Poaceae](Sea Oats) to restore foredunes. Uniola

paniculata is the dominant grass naturally occurring on foredunes along the southeast

coast of the United States (Dahl et al. 1977, Woodhouse 1978). This grass forms a dense

latticework of rhizomes and tillers, which trap sand and stabilize forming dunes (Clewell

1986). U. paniculata is planted because it tolerates salt spray, sand accumulation,

drought, and because of its dune stabilizing characteristics (Woodhouse et al. 1968,

Clewell 1986). However, multiple species plantings or "intermixed composite plantings"

may be beneficial because of potential positive interactions or facilitation among dune

plants. Also, planting more than one species increases the diversity of plants available

for wildlife.

Schizachyrium maritimum (Chapman) Nash [Poaceae]) (Gulf Bluestem), Panicum

ama~rum Ell. var. ama~rulum (A. S. Hitchc. & Chase) P.G. Palmer (Bitter Panic Grass),

and Iva imbricate Walter [Asteraceae] (Seacoast Marshelder) are three additional western









Gulf coast species commonly found on coastal dunes (Craig 1991), which are sometimes

used in restoration proj ects.

Schizachyrium maritimum is considered the most important species of bluestem

grass on the Gulf of Mexico and occurs primarily on dunes, beaches, and coastal swales

(Craig 1991). It is a perennial, short, dense, stoloniferous grass (Johnson 1997). The

plants prostrate growth habit makes it effective at trapping sand. S. maritimum is often

dominant in coastal dunes (Clewell 1986) and naturally replaces U. paniculata as soon as

a foredune ridge develops (Johnson 1997) making it a good candidate for beach proj ects

requiring planting on the backside of a primary dune and all sides of secondary dunes.

Panicum ama~rum is a perennial, warm season grass that occurs on coastal dunes

throughout the gulf coast. Although outcompeted by U. paniculata, P. ama~rum remains

a part of the permanent vegetation cover along the southeastern coast (Seneca et al. 1976,

Woodhouse 1978). P. ama~rum grows to heights of up to 213 cm and has large wide

leaves. Plantings of P. ama~rum are less affective at accumulating sand when compared

to U. paniculata and Ammophila breviligulata (Fernald) (American Beachgrass) or when

planted in combination with those species. However, P. ama~rum provides more

groundcover than U. paniculata or A. breviligulata during the same period of

establishment, which suggests it's principal value may be in stabilizing sandy coastal

areas and developing foredunes (Seneca et al. 1976).

Iva imbricate occurs on coastal dunes throughout the gulf coast and is used for

dune restoration and stabilization projects (Craig 1991). The plant has sparse, woody,

upright stems and fleshy, narrow leaves. It is prized for its ability to accumulate sand and










produce low, rounded dunes. Both I. inabricata and S. nzaritinsun have been identified as

important beach mice foods (Moyers 1996).

Sand accumulation resulting from aeolian movement of dry sand on beaches is a

major environmental factor effecting plant survival and growth. Burial is a strong

selective force and can alter the composition of plant communities (Martinez and Psuty

2004). Plant species differ in how they respond to sand accumulation. Species tolerant

of burial usually have an extensive system of both vertical stems and horizontal rhizomes

(Ehrenfeld 1990). Plant response to burial changes from positive to negative at a species'

threshold level of burial (Martinez and Psuty 2004). Foredunes species such as U.

paniculata respond to sand accumulation below burial threshold by increasing

photosynthetic rate (Yuan et al. 1993), which stimulates growth (Clewell 1986). This

allows the plant to extend above the level of sand accumulation and survive. However, if

sand accumulation exceeds a species' burial threshold then the plant is stressed, which

can lead to death. Sand accumulation also can prevent seed germination and

establishment if burial is too deep (Sykes and Wilson 1990). The stimulatory response is

the most common response of dune species to burial (Maun and Baye 1989).

Plant-plant interactions can be competitive, neutral, or facilitative. Facilitation in

plant communities occurs when a plant changes the conditions experienced by another

plant resulting in benefit to one of the plants or benefit to both mutualismm) and causing

harm to neither (Odum 1953). Facilitation may result when plants increase the nutrient

content of the soil, increase soil moisture by shading the surface, reduce evaporation,

block salt spray, increase soil stability and/or reduce herbivory or seed predation (Franks

2003b). Competition occurs when plants compete for resources to the benefit of one










plant at the expense of another. The idea that positive as well as negative or neutral

interactions may be fundamental processes in plant communities (Hunter and Aarssen

1988, Bertness and Callaway 1994, Callaway 1995) is gaining wide acceptance.

Succession refers to the changes observed in an ecological community following a

disturbance that opens up a relatively large space (Connell and Slatyer 1977).

Interspecific interactions between plants and the effect they have on local abiotic

conditions are a major force driving succession in some ecosystems (Clements et al.

1916). Facilitation is likely more important than competition in the very early stages of

succession (Bertness and Callaway 1994, Goldberg et al. 1999).

Reaction theory (Clements et al. 1916, Connell and Slayter 1977) suggests that the

reaction of the environment to plants modifies the environment so that previously

excluded plants can invade. Building on this early successional theory, the nucleated

succession model suggests early colonizing plants establish in barren areas and alter the

environment as they grow. These colonizers act as nurse plants (Niering et al. 1963)

which facilitate the establishment of late successional species (Franks 2003b). As

environmental conditions are altered and mid and late successional species become

established, competition may replace facilitation as the dominant mechanism affecting

species competition.

Successional endpoints however are not uniform and can change in response to

xeric conditions, salt spray, periodic overwash and windblown sand (Snyder and Boss

2002) resulting in changes in species dominance at different locations. Knowledge about

the stages of succession and what role facilitation plays in it could provide valuable

information about succession of coastal ecosystems.










Experiments documenting facilitation have been conducted in many diverse

ecological systems such as the Sonoran Desert, New England salt marsh, old

Saskatchewan agriculture field sites, South African shrub lands, sub arctic coastal dunes,

temperate coastal dunes, and tropical coastal dunes (Niering et al. 1963, Bertness 1991,

Bertness and Hacker 1994, Li and Wilson 1998, De Villiers et al. 2001, Gagne and Houle

2001, Franks and Peterson 2003, Martinez 2003, Rudgers and Maron 2003). Facilitation

among plants has been shown to increase in frequency as environmental stress increases

(Callaway and Walker 1997, Maestre and Cortina 2004). Thus, facilitation may play an

important role in the succession of coastal foredunes, as it is a highly stressful

environment. Knowledge about how plant species interact with each other could prove to

be valuable in dune restoration.

Interactions between plants may positively effect plant survival but negatively

affect plant growth (Franks 2003a), suggesting that interactions may be even more

complex with both facilitation and competition occurring at the same time through

different mechanisms. In addition, the balance between competitive and facilitative

interactions between plants can be affected by the life stage of the plant or as the

environment they interact with is modified (Kellman and Kading 1992, Pugnaire et al.

1996, Callaway and Walker 1997). It has also been shown that facilitative and

competitive mechanisms do not act independently of each other and can occur within the

same community and even the same individual (Callaway and Walker 1997). With such

complex interactions occurring a thorough understanding of the coastal dune systems

ecology and the physiology of the plants found in it will be necessary before we can truly

understand the different aspects of how plants are interacting.









Interactions among I. inabricata, S. nzaritinsun and P. anzarunt are not well

understood although U. paniculata seedling establishment has been found to increase

when seeds germinate within the canopy of established I. inabricata plants (Franks

2003a). Facilitation among Chamnaecrista cha~neacristoides (L.) and two late colonizing

grasses, (Schizachyrium scopariunt (Michx.) Nash and Trachypogon phenosus (Humb. &

Bonpl. ex Willd.)) in tropical dune systems along the SE coast of the Gulf of Mexico has

also been documented (Martinez 2003).

The obj ective of this experiment was to compare sand accumulation rates and

survival of monocultures and composite plantings of I. inabricata, P. a~nzaun, and S.

nzaritinsun at two plant densities. We asked the following questions. Does plant density

affect the survival of individual species? Does planting combination affect survival of

individual species? Does plant density affect sand accumulation rates for individual

species? Does planting combination affect sand accumulation rates? Does sand

accumulation have an effect on survival of individual species? Answering these

questions will help to determine if facilitation or competition between species is

occurring and what effect planting combinations have on sand accumulation and

transplant survival. This information can be used to develop efficient methods for

restoring dunes using plant combinations that provide for rapid sand accumulation and

maximum survival of all three species.

Study Site

This study was conducted on Santa Rosa Island, Florida (300 18' N, 870 16' W), a

Holocene barrier island consisting of almost 100% pure quartz sand (median diameter of

0.25 mm). Study sites were located on two nearly undeveloped sections of the island,









which are part of Eglin Air Force Base (Figure 25). The island, part of the western

panhandle of Florida, has historically been one of the most stable shorelines along the

Gulf Coast (Otvos 1982, Morton et al. 2005, Otvos 2005). However, in 1995 two major

hurricanes (Erin and Opal) impacted the Northwest Florida coast. These storms caused

extensive beach erosion and leveled a maj ority of the established frontal dunes.

Following a 9-year period of dune growth, Northwest Florida was hit by another maj or

hurricane, (Ivan), in September 2004, which caused further erosion or loss of remaining

established foredunes and flattened incipient foredunes.

The climate of Santa Rosa island is subtropical with 152 cm mean annual

precipitation and rainfall peaks in summer and late winter/early spring. Northerly winds

prevail from September-February with southerly winds the rest of the year. Highest

monthly wind speeds occur during fall, winter, and spring (Miller et al. 2001).

Methods

Experimental Design

This experiment followed a randomized complete block design arranged as a split

plot with sites as blocks, density allocated to main plots and planting combinations

allocated to subplots. Six sites, each approximately 80 m from mean high tide line where

overwash associated with hurricane Ivan's (16 September, 2004) 5 m (15 ft) storm surge

removed perennial vegetation and frontal dune elevation, were randomly chosen from

available overwash sites to serve as blocks and replicates. On Jan. 27-30 2005,

Schizachyrium maritimum, Panicum~PPP~~~~PPP~~~PPP ama~rum, and Iva imbricate, were planted in 0.6 x .9

m or 0.9 x 1.35 m subplots either 30 cm (12 in) or 44 cm (18 in) apart (density

treatments) respectively in 8 planting combinations (combination treatments) for a total

of 16 treatments. The total number of plants per combination treatment was held









constant at 12 with a random placement of each plant within the 3 rows of 4 plants

running parallel to the shoreline. Three of the combination treatments consisted of 12

plants of the same species (monoculture), three consisted of six plants each of two

different species (biculture), one consisted of four plants each of three different species

(triculture), and a control (no plants). Plants were beach planted with the top of the root

ball placed approximately 5 cm below the surface without root scoring, supplemental

watering, or fertilizer.

Data Collection

Base line and sand accumulation (change in height (cm)) at the center of each

combination treatment was measured with a laser transit at 0, 33, and 117 days after

planting (DAP), January 27, February 1, and May 24 respectively. Accumulation levels

were calculated for three periods 0-33 DAP (period one), 33-117 DAP (period two), and

Total sand accumulation.

Survival was recorded as the presence of any living shoot visible above the sand at

130 DAP. Total survival was determined for each subplot to determine plant density. To

determine differences in survival of each species among treatments, a random subset of

four plants per species from each treatment was used to standardize n.

Analysis

Data was subj ected to Proc Mixed Procedure of SAS to perform a repeated

measures analysis of variance (SAS Institute Inc. 2000-2004). Contrast statements were

used to determine significant differences between planting combinations. Significance of

main effects for survival was determined using the Proc Genmod procedure of SAS (SAS

Institute Inc. 2000-2004).









Results

Sand Accumulation

Sand accumulated significantly more than bare sand controls in all planting

combinations during the first 33 DAP (Table 4). All planting combinations except S.

maritimum monocultures continued to gain significant amounts of sand for the remainder

of the measurement period. Effects of planting combination and spacing on sand

accumulation were significant. There was no significant interaction between spacing and

planting combination.

Total mean sand accumulation for P. ama~rum planted in monoculture was

significantly higher than when planted in combination with another species. Mean

accumulation for I. imbricata planted in monoculture did not differ significantly from

mean accumulation when planted in combination with another species for any

accumulation period. S. maritimum planted in monoculture had significantly higher

mean accumulation than when planted in combination with other species for the first 33

DAP but had significantly lower mean accumulation for period two and Total

accumulation.

Mean sand accumulation was significantly higher (P = 0.0239) for 30 cm spacing

compared to 44 cm spacing 33 DAP but did not differ significantly (P = 0.8109) between

spacing treatments during period two. Total mean accumulation was significantly higher

(P = 0.003 8) at 30 cm compared to 44 cm spacing.

Monoculture plantings ofP. ama~rum had a significantly higher mean sand

accumulation than biculture plantings during all periods while monoculture plantings of I.

imbricata did not have significantly different mean accumulation when compared to

biculture plantings for all periods. Monoculture plantings of S. maritimum had










significantly higher accumulation rates than biculture plantings 33 DPA. However,

accumulation was significantly lower for period two and Total accumulation. Triculture

plantings did not differ significantly from biculture plantings for any accumulation

period.

Survival

Mean survival varied from 18 to 90% between the two grass species. Survival of

P. ama~rum ranged form 75% to 100% for all spacing and planting combinations (Table

5). Differences among treatments were not detectable for P. ama~rum as all survival fell

above 75%. Survival of S. maritimum ranged from 8 to 29% for all density and planting

combinations. Survival was significantly higher (P = 0.0245) at 44 cm spacing where

maximum plant foliage burial was 35% compared to 43% burial at 30 cm spacing.

Planting combination did not have a significant effect on S. maritimum survival (P =

0.6607).

Survival of L imbricata ranged from 54% to 92% for all spacing and planting

combinations. Survival did not differ significantly for 44 cm compared to 30 cm spacing

(P = 0.0879). Planting combination significantly affected survival (P = 0.0029).

Survival of L imbricata was lower (P = 0.0313) when planted in combination with P.

ama~rum (Table 5).

Discussion

Higher density plantings accumulated more sand during winter months. However,

the effect of plant density and plant species on sand accumulation changed during spring

months. The decreased relative difference in percent ground coverage by aboveground

plant parts among species and planting combination with active spring growth and low

survival of S. maritimum may cause this change. Initially, the wider spaced plantings










(lower plant density) corresponded to lower percent foliar and basal coverage. As a

result, wider spaced plantings presented less resistance to sand movement and thus, lower

accumulation occurred. As plants began to grow bare areas between plants were reduced

resulting in relatively less difference in exposed area between plantings spaced

differently and therefore, the ability of sand to move in and out freely was similar

between plantings. Although differences in percent cover can be initially assumed due to

difference in plant density and uniformity of transplants, growth data would have

quantified the change in percent cover. However, growth data was not collected before

the loss of the experiment by overwash during tropical storm Arlene (June 1 1, 2005).

The negative accumulation rate of monoculture plantings of S. maritimum during

spring months (March May) appeared to result from high plant mortality. After plant

death, the subsequent deconstruction of the dead foliage during the months of March -

May released the previously trapped sand. Lower accumulation rates for plantings ofP.

ama~rum in combination with other species may be a result of the replacement of P.

ama~rum plants with I. imbricate, which was less effective than P. ama~rum at trapping

sand. Death of a high percentage of S. maritimum also resulted in lower sand

accumulation when planted with P. amarum.

In this study, I found no evidence of facilitation among P. ama~rum, L. imbricate

and S. maritimum when planted in combination and at densities generally used in dune

restoration. These results contradict those of (Franks and Peterson 2003) who suggested

facilitation at higher densities positively effects plant survival and plant biomass in buried

plots. Franks and Peterson also found that species richness had no effect on survival or

biomass when plants were buried. However, there were differences between the two









studies. Both density levels of my study fell between the high (50 cm) and low (20 cm)

density levels of the Franks and Peterson study. In addition to I. inabricata, which was

included in both studies, Franks and Peterson included different grasses, herbs, shrubs

and vines, which were planted during the active growing season (July) and burial was

applied as a one-time event.

Greater sand accumulation associated with increased planting density appears to

have negatively impacted survival of S. nzaritinsun. After 33 days, the crowns of S.

nzaritinsun transplants were as much as 12.7 cm below the soil surface and as much as

43% of the foliage was buried which may have exceeded the threshold level of burial

(Martinez and Psuty 2004), subj ecting the plants to stress and possibly causing death

Similarly, Franks and Peterson (2003), found a 54% reduction in survival when several

dune species were buried to approximately 50% of their height. S. nzaritinsun as a

secondary colonizing grass replaces U. paniculata behind foredune ridges (Johnson

1997). Because S. nzaritinsun is often found on the leeward side of dunes where sand

movement and salt deposition are reduced (Craig 1991), it may be less tolerant of sand

burial although salt spray tolerance can also influence plant zonation (Oosting 1945).

Two secondary colonizing grasses, Schizachyrium scopariunt and Trachypogon phenosis

have also been shown to be intolerant of high levels of sand burial and are restricted to

areas where sand movement is decreased (Martinez et al. 2001).

However, my findings contradict an earlier study that found artificial burial with

sand of 50 or 100% of foliar tissue increased plant dry weight of Schizachyrium

scopariunt above that of unburied controls Martinez and Moreno-Casasola (1996).

Results for S. scopariunt were recorded when plants were artificially buried while plants









were actively growing (summer) as opposed to the results of my study where planting

and natural sand burial occurred while plants were dormant (winter). Changes in

environmental factors such as soil moisture and soil temperature in response to burial are

the most important factors effecting plant growth and survival (Martinez et al. 2001).

Burial during winter months may have decreased soil temperature and increased soil

moisture to the detriment of plant survival.

Wind speeds, sand movement and accumulation are greatest during winter months

on Santa Rosa Island and may represent the least advantageous time to plant S.

nzaritinsunt Miller et al. 2001 In this stud S. nzaitinsun survival was < 29% when

planted in January in an overwash site on Santa Rosa Island. Yet, earlier studies on this

island found 100% survival 2 1/2 yrs after planting when S. naritinsun was planted

during summer months behind a developing dune ridge (Thetford et al. 2005) and 100%

survival (June until uprooted by hurricane Ivan (16 September, 2004)) when planted

between condominiums less than 40 m from mean high tide line with no other dune

structure landward of the planting (unpublished data). Conditions during winter months

may limit the ability of S. naritinsun to persist in foredunes with high sand accumulation

rates. Future experiments are needed to determine what environmental factor or factors

are responsible for the reduced survival of S. naritinsun when planted in a foredune

location during winter months.

Competition from P. anzarunt may be responsible for the lower survival rates of L

inabricata. Franks (2003a) found reduced biomass of I. inabricata when planted in

combination with U. paniculata, however he found an increase in survival of I. inabricata










suggesting the simultaneous occurrence of facilitation and competition. Further research

is needed to determine the tolerance of L inabricata to competition.

P. anzarunt is reported to be less tolerant of burial than thriola paniculata and

Ananophila breviligulata, especially during establishment (Woodhouse 1982); however,

we found high survival rates during winter months when sand accumulation is highest for

Santa Rosa Island (Miller et al. 2001). Survival rates ranging from 75% to 82% have

been recorded for spring plantings ofP. anzarunt (Seneca et al. 1976, Miller et al. 2001),

which are similar to the survival rates found in this study. P. a~nzaun spreads faster at

sites receiving moderate amounts of sand accumulation compared to sites receiving little

sand accumulation (Seneca et al. 1976). Moderate amounts of burial by sand have been

shown to result in higher plant density, percent cover, and biomass per plant below a

certain threshold level of burial (Maun 1998). My results suggest P. anzarunt is below its

burial threshold when planted alone or in combination with plants and at densities used in

this experiment in frontal dunes of Santa Rosa Island.

Greater tolerance of P. anzarunt and I. inabricata to sand burial compared to S.

nzaritinzun may result from differences in height and growth form among species. S.

nzaritinsun 's low, prostrate growth may reduce its ability to tolerate burial resulting in the

low survival rates seen in this experiment. However, S. nzaritinsun 's may also be less

tolerant of salt spray and the increased wind speeds and sand movement during winter

months may have increased salt exposure. The upright growth form ofL. inabricata

transplants may confer an ability to tolerate sand accumulation. This species tolerance to

saltwater overwash, saltspray, and sandblasting may also contribute to its survival when

transplanted on an overwash site (Woodhouse 1982).










Conclusions

Effects of intermixed composite plantings on survival of P. ama~rum, L. imbricate,

and S. maritimum ranged from neutral to negative when compared to monoculture

plantings. The effect of composite plantings on mean sand accumulation when compared

to monoculture plantings was neutral or negative for all species when compared to

monoculture plantings.

Survival rates of L imbricate were reduced when planted in combination with other

species, possibly as a result of interspecific competition, especially when planted in

combination with P. ama~rum.

High plant density (30 cm spacing) compared to low plant density (44 cm spacing)

increased sand accumulation. However, increased burial may have led to high mortality

rates for S. maritimum. Threshold level of burial for individual species determines

whether or not increasing the initial rate of sand accumulation with higher plant density

will have a negative affect on transplant survival rates. The varying responses to burial

suggest that some species have a higher threshold of burial and will be better suited to

rapid dune formation and some species will have a lower threshold level of burial and

should be planted in areas or orientations where they are less likely to accumulate sand as

quickly. This will result in increased survival rates and increase the efficiency of

restoration.













































O 510 kmn

*Reprinted with permission of the
publisher

Figure 25. Map of Florida with insert showing the location of Santa Rosa Island. Arrows
indicate the location of the six study sites and Santa Rosa Sound.












Table 4. Incremental and Total sand accumulation (cm) of height gained for 30
cm and 44 cm spacings of Iva imbricate, Panicum ama~rum, and
Schizachyrium maritimum planted in different combinations of 12
plants including a control (no plants). Combinations consisting of two
species have six plants of each species planted and combinations
consisting of three species have four plants of each species planted.
Iva = Iva imbricata, Pan = Panicum ama~rum, Sch = Schizachyrium
maritimum. Analysis of variance for main effects and contrasts,
si nificance at P < 0.05.
Period of Accumulation (days)
0-33 33-117 0-117

Spacing (cm)
Planting Combination 30 44 30 44 30 44


Control 3.43-1.14 -1.45-0.91 1.98 -2.06
Iva 6.78 0.76 2.21 4.42 8.99 5.18
Pan 8.23 2.82 4.80 5.41 13.03 8.23
Sch 7.85 3.66 -0.50-1.37 3.35 2.29
Iva+Pan 3.43 1.98 4.65 3.28 8.08 5.26
Iva+Sch 1.68 1.98 1.52 0.23 3.20 2.21
Pan+Sch 4.34 3.66 2.67 1.75 7.01 5.41
Iva+Pan+Sch 3.96 3.05 3.35 2.13 7.32 5.18


Analysis of Variance df

Main effects p-value p-value p-value
Rep 3 0.3548 0.4559 0.0232
Spacing 1 0.0592 0.8109 0.0038
Planting Combination 7 0.0542 <.0001 <.0001
Spacing*Planting Combination 7 0.3040 0.4116 0.9291
Contrasts
Control versus Iva 1 0.0975 0.0005 0.0002
Control versus Pan 1 0.0072 <.0001 <.0001
Control versus Sch 1 0.0049 0.1483 0.1072
Iva versus Iva+Pan, Iva+Sch 1 0.2689 0.3899 0.1179
Pan versus Pan+lva, Pan+Sch 1 0.1134 0.0567 0.0078
Sch versus Sch+lva, Sch+Pan 1 0.0588 0.0013 0.0002
Iva+Pan, Iva+Sch, Pan+Sch versus 1 0.6048 0.6874 0.4616
Iva+Pan+Sch










Table 5. Mean survival (percent) for 30 cm and 44 cm spacings of Iva imbricate,
Panicum~PPP~~~~PPP~~~PPP ama~rum, and Schizachyrium maritimum planted in different
combinations of 12 plants. Combinations consisting of one species
have 12 plants of the same species planted and combinations
consisting of two species have six plants of each species planted.
Combinations consisting of three species have four plants of each
species planted. Iva = Iva imbricate, Pan = Panicum~PPP~~~~PPP~~~PPP ama~rum, Sch =
Schizachyrium maritimum.
Survival%
Iva Pan Sch

Spacing (cm)
Planting Combination 30 44 30 44 30 44
Iva 88 92
Pan 96 92
Sch 17 29
Iva+Pan 63 54 88 75
Iva+Sch 58 92 8 29
Pan+Sch 83 96 8 21
Iva+Pan+Sch 71 83 100 88 17 17

Analysis of Variance df p-value p-value p-value
Main effects
Rep 5 0.0909 <.0001
Spacing 1 0.0879 0.0245
Rep*Spacing 5 0.9619 0.3595
Planting Combination 3 0.0029 0.6607
Contrasts
Iva versus Iva+Pan 1 0.0313**
Iva versus Iva+Sch 1 0.3844**















APPENDIX
IVEANS AND STANDARD ERRORS FOR IVA IM~BRICA TA
PROPAGATION STUDY

Table 6. Iva imbricate stock-plants mean height (cm) and standard deviation of
by harvest and fertility rate using repeated measures of proc mixed
(SAS Institute Inc. 2000-2004). Fertilizer rate (fert) = fertility rates in
(g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114,
146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49,
79, 108, and 136 days after potting.
Experiment 1 Experiment 2
harvest fert N Mean Std dev harvest fert N Mean Std dev
1 5.5 12 26.6 6.26 1 5.5 12 27.2 4.86
1 11 12 38.4 5.74 1 11 12 29.6 7.50
1 15 12 40.8 5.36 1 15 12 31.2 5.02
1 21 12 40.8 6.81 1 21 12 30.4 5.33
2 5.5 12 28.5 4.64 2 5.5 12 30.1 3.55
2 11 12 34.0 4.65 2 11 12 30.2 3.30
2 15 12 31.9 3.80 2 15 12 29.4 4.23
2 21 12 33.6 4.48 2 21 12 28.8 3.31
3 5.5 12 33.8 2.78 3 5.5 12 27.4 2.02
3 11 12 36.3 4.17 3 11 12 25.7 3.60
3 15 12 37.6 5.44 3 15 12 26.7 2.80
3 21 12 36.7 3.38 3 21 12 25.6 2.71
4 5.5 12 30.6 4.93 4 5.5 12 26.5 3.23
4 11 12 35.1 4.44 4 11 12 26.7 4.08
4 15 11 34.6 3.83 4 15 12 26.9 3.06
4 21 12 37.9 4.36 4 21 12 23.0 4.97











Table 7. Iva imbricate stock-plants mean width (cm) and standard deviation of
by harvest and fertility rate using repeated measures of proc mixed
(SAS Institute Inc. 2000-2004). Fertilizer rate (fert) = fertility rates in
(g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114,
146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49,
79, 108, and 136 days after potting.
Experiment 1 Experiment 2
harvest fert N Mean Std dev harvest fert N Mean Std dev
1 5.5 12 11.0 2.79 1 5.5 12 10.6 1.88
1 11 12 20.0 3.53 1 11 12 13.7 3.46
1 15 12 22.5 3.10 1 15 12 13.2 2.80
1 21 12 24.8 4.39 1 21 12 13.5 1.79
2 5.5 12 13.5 2.60 2 5.5 12 13.9 3.12
2 11 12 21.3 2.41 2 11 12 20.1 2.42
2 15 12 22.7 1.98 2 15 12 17.8 5.14
2 21 12 24.7 2.53 2 21 12 20.3 2.55
3 5.5 12 14.2 2.19 3 5.5 12 13.8 3.91
3 11 12 22.5 2.28 3 11 12 21.4 3.95
3 15 12 23.6 2.25 3 15 12 19.0 3.92
3 21 12 26.3 3.32 3 21 12 21.4 3.06
4 5.5 12 16.5 2.37 4 5.5 12 14.3 3.68
4 11 12 24.9 3.57 4 11 12 24.1 4.54
4 15 11 26.6 2.74 4 15 12 19.8 5.47
4 21 12 29.4 3.52 4 21 12 22.9 4.27










Table 8. Iva imbricata stock-plants mean index (cm3) and standard deviation of
by harvest and fertility rate using repeated measures of proc mixed
(SAS Institute Inc. 2000-2004). Fertilizer rate (fert) = fertility rates in
(g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114,
146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49,
79, 108, and 136 days after potting.
Experiment 1 Experiment 2

harvest fert N Mean Std dev harvest fert N Mean Std dev
1 5.5 12 18.8 4.42 1 5.5 12 18.9 2.86
1 11 12 29.2 4.03 1 11 12 21.7 4.15
1 15 12 31.7 3.46 1 15 12 22.2 3.32
1 21 12 32.8 4.60 1 21 12 21.9 2.59
2 5.5 12 21.0 3.21 2 5.5 12 22.0 2.93
2 11 12 27.7 2.77 2 11 12 25.1 1.99
2 15 12 27.3 2.36 2 15 12 23.6 4.31
2 21 12 29.1 3.05 2 21 12 24.5 2.36
3 5.5 12 24.0 1.76 3 5.5 12 20.6 2.64
3 11 12 29.4 2.23 3 11 12 23.5 2.39
3 15 12 30.6 2.41 3 15 12 22.9 2.71
3 21 12 31.5 2.57 3 21 12 23.5 1.93
4 5.5 12 23.5 3.21 4 5.5 12 20.4 3.12
4 11 12 30.0 3.36 4 11 12 25.4 3.25
4 15 11 30.6 2.20 4 15 12 23.4 3.83
4 21 12 33.7 2.81 4 21 12 22.9 3.39











Table 9. Iva imbricate stock-plants mean total fresh weight (g) and standard
deviation of by harvest and fertility rate using repeated measures of
proc mixed (SAS Institute Inc. 2000-2004). Fertilizer rate (fert) =
fertility rates in (g) Osmocote/1 gallon container. Experiment 1,
harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment
2, harvests 1-4 = 49, 79, 108, and 136 days after potting.
Experiment 1 Experiment 2

harvest fert N Mean Std dev harvest fert N Mean Std dev
1 5.5 12 8.0 4.45 1 5.5 12 3.2 2.05
1 11 12 24.5 8.26 1 11 12 4.7 2.56
1 15 12 40.2 7.82 1 15 12 6.4 3.00
1 21 12 45.1 15.45 1 21 12 7.9 2.31
2 5.5 12 5.3 1.67 2 5.5 12 7.4 1.68
2 11 12 17.9 5.38 2 11 12 10.9 2.93
2 15 12 21.4 4.07 2 15 11 12.2 3.17
2 21 12 28.9 7.05 2 21 12 11.9 3.50
3 5.5 12 7.7 1.47 3 5.5 12 5.1 3.04
3 11 12 16.0 2.11 3 11 10 8.4 3.07
3 15 12 20.8 2.47 3 15 12 7.3 3.16
3 21 12 26.6 4.02 3 21 12 9.9 4.82
4 5.5 12 9.2 2.80 4 5.5 11 6.3 3.34
4 11 12 21.5 4.67 4 11 11 13.0 4.98
4 15 11 28.1 4.22 4 15 11 14.3 7.63
4 21 12 34.9 5.18 4 21 12 14.9 8.44











Table 10. Mean number and standard deviation of cuttings harvested from oflva
imbricate stock-plants by harvest and fertility rate using repeated
measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate
(fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4
= 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-
4 = 49, 79, 108, and 136 days after potting.
Experiment 1 Experiment 2

harvest fert N Mean Std dev harvest fert N Mean Std dev
1 5.5 12 4.0 0.74 1 5.5 12 3.5 1.93
1 11 12 7.6 2.23 1 11 12 4.9 3.15
1 15 12 12.6 3.75 1 15 12 7.0 3.84
1 21 12 11.2 3.13 1 21 12 8.6 2.31
2 5.5 12 7.5 2.35 2 5.5 12 7.3 2.27
2 11 12 17.5 5.45 2 11 12 11.1 2.68
2 15 12 23.6 4.42 2 15 12 10.3 4.52
2 21 12 27.2 6.56 2 21 12 10.1 3.63
3 5.5 12 8.5 2.39 3 5.5 12 3.5 2.02
3 11 12 18.4 4.12 3 11 12 5.7 3.80
3 15 12 24.2 4.30 3 15 12 5.8 2.63
3 21 12 30.8 5.22 3 21 12 6.8 3.49
4 5.5 12 10.1 3.00 4 5.5 12 4.2 2.98
4 11 12 22.5 5.65 4 11 12 8.1 4.66
4 15 11 30.3 5.18 4 15 12 8.4 5.09
4 21 12 34.5 5.90 4 21 12 9.7 6.87











Table 11. Mean cutting weight (g) and standard deviation of cuttings harvested
from of Iva imbricata stock-plants by harvest and fertility rate using
repeated measures of proc mixed (SAS Institute Inc. 2000-2004).
Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1,
harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment
2, harvests 1-4 = 49, 79, 108, and 136 days after potting.
Experiment 1 Experiment 2
harvest fert N Mean Std dev harvest fert N Mean Std dev
1 5.5 12 1.6 0.66 1 5.5 12 0.9 0.28
1 11 12 2.3 1.06 1 11 12 1.0 0.42
1 15 12 2.0 0.46 1 15 12 1.0 0.20
1 21 12 2.6 0.65 1 21 12 0.9 0.14
2 5.5 12 0.7 0.01 2 5.5 12 1.1 0.27
2 11 12 1.0 0.02 2 11 12 1.0 0.18
2 15 12 0.9 0.01 2 15 11 1.1 0.25
2 21 12 1.1 0.01 2 21 12 1.2 0.21
3 5.5 12 0.9 0.18 3 5.5 12 1.5 0.32
3 11 12 0.9 0.16 3 11 10 1.3 0.35
3 15 12 0.9 0.13 3 15 12 1.4 0.31
3 21 12 0.9 0.12 3 21 12 1.4 0.18
4 5.5 12 0.9 0.10 4 5.5 11 1.5 0.40
4 11 12 1.0 0.19 4 11 11 1.5 0.26
4 15 11 1.0 0.22 4 15 11 1.6 0.29
4 21 12 1.0 0.14 4 21 12 1.7 0.32











Table 12. Mean root length (cm) and standard deviation of cuttings harvested
from of Iva imbricata stock-plants by harvest and fertility rate using
repeated measures of proc mixed (SAS Institute Inc. 2000-2004).
Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1,
harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment
2, harvests 2-4 = 79, 108, and 136 days after potting.
Experiment 1 Experiment 2
harvest fert N Mean Std dev harvest fert N Mean Std dev
1 5.5 46 6.2 3.01* **
1 11 43 7.1 3.71* **
1 15 42 5.1 2.81* **
1 21 44 4.7 2.57* **
2 5.5 38 3.4 1.55 2 5.5 48 9.6 3.15
2 11 38 3.6 1.94 2 11 48 11.4 3.24
2 15 34 2.9 1.87 2 15 44 12.2 3.16
2 21 26 3.3 2.61 2 21 46 12.3 3.23
3 5.5 30 3.3 1.66 3 5.5 35 5.0 2.20
3 11 25 3.9 2.38 3 11 38 4.9 2.86
3 15 25 3.5 2.33 3 15 42 5.0 2.34
3 21 17 3.9 2.12 3 21 45 5.4 2.33
4 5.5 48 4.9 2.93 4 5.5 31 2.3 1.33
4 11 44 5.6 2.74 4 11 36 1.9 1.70
4 15 48 5.8 2.96 4 15 31 1.7 1.33
4 21 48 6.3 3.31 4 21 40 2.0 1.97











Table 13. Mean root number and standard deviation of cuttings harvested from of
Iva imbricate stock-plants by harvest and fertility rate using repeated
measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate
(fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4
= 114, 146, 175, and 206 days after potting. Experiment 2, harvests 2-
4 = 79, 108, and 136 days after potting.
Experiment 1 Experiment 2
harvest fert N Mean Std dev harvest fert N Mean Std dev
1 5.5 46 8.7 4.03* **
1 11 43 9.7 4.55* **
1 15 42 6.5 4.70* **
1 21 44 6.4 4.09* **
2 5.5 38 5.8 2.93 2 5.5 48 11.5 5.04
2 11 38 6.0 3.71 2 11 48 12.0 5.23
2 15 34 4.8 3.34 2 15 44 14.7 4.85
2 21 26 4.3 3.26 2 21 46 13.9 5.04
3 5.5 29 4.6 2.80 3 5.5 35 9.1 3.85
3 11 25 4.7 3.06 3 11 38 6.2 3.40
3 15 25 4.2 4.36 3 15 42 8.9 3.90
3 21 17 4.1 3.93 3 21 45 8.0 3.13
4 5.5 48 6.0 3.36 4 5.5 35 6.9 4.20
4 11 44 6.2 2.90 4 11 44 5.1 3.77
4 15 48 6.4 2.86 4 15 42 5.5 4.78
4 21 48 6.9 3.48 4 21 46 5.9 4.01











Table 14. Mean root index (cm) and standard deviation of cuttings harvested
from of Iva imbricata stock-plants by harvest and fertility rate using
repeated measures of proc mixed (SAS Institute Inc. 2000-2004).
Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1,
harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment
2, harvests 2-4 = 79, 108, and 136 days after potting.
Experiment 1 Experiment 2

harvest fert N Mean Std dev harvest fert N Mean Std dev
1 5.5 46 57.5 41.0* **
1 11 43 77.3 62.1* **
1 15 42 37.8 37.0* **
1 21 44 36.3 36.4* **
2 5.5 38 22.3 15.3 2 5.5 48 111.4 58.9
2 11 38 27.0 24.3 2 11 48 136.3 66.4
2 15 34 17.5 18.3 2 15 44 179.2 68.2
2 21 26 21.0 33.8 2 21 46 174.3 85.5
3 5.5 29 16.9 15.3 3 5.5 35 47.7 27.1
3 11 25 22.5 19.9 3 11 38 35.3 27.2
3 15 25 21.9 31.1 3 15 42 48.4 36.1
3 21 17 20.2 26.8 3 21 45 47.0 27.4
4 5.5 48 35.5 34.7 4 5.5 31 19.6 14.3
4 11 44 37.9 26.7 4 11 36 13.4 15.3
4 15 48 41.2 29.9 4 15 31 14.0 14.9
4 21 48 49.1 35.0 4 21 40 14.7 16.6











Table 15. Mean rooting percentage and standard deviation of cuttings harvested
from of Iva imbricata stock-plants by harvest and fertility rate using
repeated measures of proc mixed (SAS Institute Inc. 2000-2004).
Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1,
harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment
2, harvests 2-4 = 79, 108, and 136 days after potting.
Experiment 1 Experiment 2

harvest fert N Mean % Std dev harvest fert N Mean % Std dev
1 5.5 48 95.8 20.19 **
1 11 48 89.6 30.87 **
1 15 48 87.5 33.42 **
1 21 48 91.7 27.93 **
2 5.5 48 79.2 41.04 2 5.5 48 100.0 0.00
2 11 48 79.2 41.04 2 11 48 100.0 0.00
2 15 48 70.8 45.93 2 15 48 91.7 27.93
2 21 48 54.2 50.35 2 21 48 95.8 20.19
3 5.5 48 62.5 48.92 3 5.5 48 72.9 44.91
3 11 48 52.1 50.49 3 11 46 78.3 41.70
3 15 48 52.1 50.49 3 15 48 87.5 33.42
3 21 48 35.4 48.33 3 21 47 93.6 24.71
4 5.5 46 100.0 0.00 4 5.5 48 64.6 48.33
4 11 47 91.5 28.21 4 11 48 75.0 43.76
4 15 47 100.0 0.00 4 15 48 64.6 48.33
4 21 47 100.0 0.00 4 21 48 83.3 37.66
















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BIOGRAPHICAL SKETCH

Josiah graduated from Pensacola High School in 1992. He took many college prep

courses during high school but did not begin college until 1997. Josiah worked various

jobs that ranged from cooking in a seafood restaurant to working as an automobile

mechanic. The skills that he learned during that time are still valuable lessons in his life

today. He began his college career by attending Pensacola Junior College from January

1997 to December 1999. After graduating with honors with an A.A. degree in

environmental horticulture, he was accepted by the University of Florida to continue his

college education. He began classes in the University of Florida' s Environmental

Horticulture program located at the West Florida Research and Educational Center in

Milton, Florida, where he attended classes from January 2001 to May 2002. Josiah

graduated as a University Scholar with highest honors. While at the West Florida

Research and Educational Center he completed an undergraduate research proj ect

observing the genetic diversity of 'Red Baron' Cogongrass. He presented his research at

the southern Nurseryman Association conference and was awarded first place in the

undergraduate research competition. Josiah worked as a Sr. Laboratory Technician under

Dr. Mack Thetford during the final semester of his undergraduate degree. He continued

to manage his lab group until December 2003 when he left to attend Graduate School at

the University of Florida in Gainesville. Josiah entered the master' s program in

interdisciplinary ecology in the School of Natural Resources and Conservation. In

Gainesville, he began to study coastal restoration, specifically looking at plant









interactions during dune restoration. Hurricanes and tropical storms repeatedly destroyed

his research, but he was able to gather enough information to complete his thesis. Josiah

currently works with the Department of Environmental Protection in Pensacola, Florida.

He does not see himself continuing his education in a university setting.

When asked to look back at his college career, Josiah states that there are two

important factors that stand out in his mind. First, the time he took off between high

school and college taught him many things that helped him become better student. The

second is financial aid, without which, he would not have been able to afford to go to

college.




Full Text

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GULF COAST BARRIER ISLAND RESTORATION: PUBLIC DEMONSTRATION AND EDUCATION, PRODUCTION PRACTICES FOR THE BEACH PLANT Iva imbricata AND RESTORATION WITH COMPOSITE PLANTINGS By JOSIAH SHANE RAYMER A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2006

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Copyright 2006 by Josiah Shane Raymer

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This document is dedicated to everyone who has helped me survive my college career.

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ACKNOWLEDGMENTS I would like to thank all of the people who have helped me with my research. I thank all of the teachers who have passed on their knowledge to me; I will try and put it to good use. In particular I would like to thank Mack Thetford and Debbie Miller whose guidance helped immensely in the creation of this thesis, Rick Schoellhorn for being a friend, Peggy Olive for telling me learning is more important than good grades, and lastly, I want to thank my friends who have helped me during the past several years and supported me being a student. iv

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TABLE OF CONTENTS Page ACKNOWLEDGMENTS .................................................................................................iv LIST OF TABLES ............................................................................................................vii LIST OF FIGURES ...........................................................................................................ix ABSTRACT ......................................................................................................................xii CHAPTER 1 INTRODUCTION........................................................................................................1 2 DEMONSTRATION PLANTINGS AT NAVARRE BEACH (SANTA ROSA ISLAND, FL)................................................................................................................3 Percent of Responses..................................................................................................11 Difference Between Pre and Post Program Responses...............................................11 3 EFFECT OF FERTILITY RATE ON CUTTING PRODUCTION OF STOCK-PLANTS OF Iva imbricata: ROOTING CHARACTERISTICS OF CUTTINGS PRODUCED...............................................................................................................12 Introduction.................................................................................................................12 Materials and Methods...............................................................................................14 Results and Discussion...............................................................................................16 Experiment One...................................................................................................16 Stock-plant growth and cutting production..................................................16 Rooting percentages and quality..................................................................19 Experiment Two..................................................................................................20 Stock-plant growth and cutting production..................................................20 Rooting percentages and quality..................................................................21 Discussion...................................................................................................................23 4 RESTORATION OF FOREDUNES WITH INTERMIXED COMPOSITE PLANTINGS..............................................................................................................40 Introduction.................................................................................................................40 Study Site....................................................................................................................45 Methods......................................................................................................................46 Experimental Design...........................................................................................46 Data Collection....................................................................................................47 v

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Analysis...............................................................................................................47 Results.........................................................................................................................48 Sand Accumulation.............................................................................................48 Survival................................................................................................................49 Discussion...................................................................................................................49 Conclusions.................................................................................................................54 APPENDIX MEANS AND STANDARD ERRORS FOR Iva imbricata PROPAGATION STUDY.......................................................................................................................58 LIST OF REFERENCES...................................................................................................68 BIOGRAPHICAL SKETCH.............................................................................................73 vi

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LIST OF TABLES Table page 1 Results of preprogram and postprogram survey taken by ten coastal restoration workshop participants..............................................................................................11 2 Main effects by measured variable and experiment for total fresh weight cuttings, number of cuttings produced, and fresh weight of individual cuttings....................38 3 Main effects by measured variable and experiment for mean percent rooting, root number, root length, and root index (root number root length)............................39 4 Incremental and total sand accumulation (cm) of height gained for 30 cm and 44 cm spacings of Iva imbricata, Panicum amarum, and Schizachyrium maritimum planted in different combinations of 12 plants including a control (no plants). Combinations consisting of two species have six plants of each species planted and combinations consisting of three species have four plants of each species planted. Iva = Iva imbricata, Pan = Panicum amarum, Sch = Schizachyrium maritimum. Analysis of variance for main effects and contrasts, significance at P < 0.05.........56 5 Mean survival (percent) for 30 cm and 44 cm spacings of Iva imbricata, Panicum amarum, and Schizachyrium maritimum planted in different combinations of 12 plants. Combinations consisting of one species have 12 plants of the same species planted and combinations consisting of two species have six plants of each species planted. Combinations consisting of three species have four plants of each species planted. Iva = Iva imbricata, Pan = Panicum amarum, Sch = Schizachyrium maritimum................................................................................................................57 6 Iva imbricata stock-plants mean meight (cm) and standard deviation of by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertilizer rate (fert) = fertility rates in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting.....................58 7 Iva imbricata stock-plants mean width (cm) and standard deviation of by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertilizer rate (fert) = fertility rates in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting.....................59 vii

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8 Iva imbricata stock-plants mean index (cm 3 ) and standard deviation of by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertilizer rate (fert) = fertility rates in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting.....................60 9 Iva imbricata stock-plants mean total fresh weight (g) and standard deviation of by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertilizer rate (fert) = fertility rates in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting.....................61 10 Mean number and standard deviation of cuttings harvested from of Iva imbricata stock-plants by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting.....................62 11 Mean cutting weight (g) and standard deviation of cuttings harvested from of Iva imbricata stock-plants by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting.....................63 12 Mean root length (cm) and standard deviation of cuttings harvested from of Iva imbricata stock-plants by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 2-4 = 79, 108, and 136 days after potting...........................64 13 Mean root number and standard deviation of cuttings harvested from of Iva imbricata stock-plants by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 2-4 = 79, 108, and 136 days after potting...........................65 14 Mean root index (cm) and standard deviation of cuttings harvested from of Iva imbricata stock-plants by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 2-4 = 79, 108, and 136 days after potting...........................66 15 Mean rooting percentage and standard deviation of cuttings harvested from of Iva imbricata stock-plants by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 2-4 = 79, 108, and 136 days after potting...........................67 viii

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LIST OF FIGURES Figure page 1 Preprogram and postprogram survey used to evaluate change in knowledge of coastal restoration workshop participants..................................................................8 2 Backside of Beachgoers Guide to Sand Dunes trifold brochure created for demonstration project.................................................................................................9 3 Frontside of Beachgoers Guide to Sand Dunes trifold brochure created for demonstration project...............................................................................................10 4 Plant height by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................27 5 Plant width by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................27 6 Plant growth index ((mean width + ht)/2) by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0..................................................28 7 Total fresh weight cuttings by fertility rate and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0..................................................................28 8 Cutting number produced by fertility rate and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0..................................................................29 9 Cutting weight by fertility rate and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................29 10 Percent rooting by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................30 11 Root number by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................30 ix

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12 Root length by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................31 13 Root index by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................31 14 Plant height by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................32 15 Plant width by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................32 16 Plant growth index ((mean width + ht)/2) by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0..................................................33 17 Total fresh weight cuttings by fertility rate and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0..................................................................33 18 Cutting number produced by fertility rate and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. ................................................................34 19 Cutting weight by fertility rate and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................34 20 Percent rooting by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.........................................................................35 21 Root number by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................35 22 Root length by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................36 23 Root index by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...........................................................................................36 x

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24 Mean fresh weight of cuttings by run, fertility rate, and month of harvest. Exp1 = Experiment 1, Exp2 = Experiment 2. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month @ 70 F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0...................37 25 Map of Florida with insert showing the location of Santa Rosa Island. Arrows indicate the location of the six study sites and Santa Rosa Sound...........................55 xi

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Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science GULF COAST BARRIER ISLAND RESTORATION: PUBLIC DEMONSTRATION AND EDUCATION, PRODUCTION PRACTICES FOR THE BEACH PLANT Iva imbricata, AND RESTORATION WITH COMPOSITE PLANTINGS By Josiah Shane Raymer May 2006 Chair: Deborah Miller Major Department: Natural Resources and Environment In order to promote plant diversity and increase wildlife habitat, residents, contractors, and local officials need exposure to the benefits of using more than one plant species for dune restoration. This was accomplished through a demonstration planting, an educational kiosk, a brochure, and a website. Education of the public occurred when materials were presented at a variety of meetings, workshops, and events. Workshop participants were aware of the values of dunes but were less knowledgeable about individual plants that grow in the coastal dune system. Ninety percent of the participants gained some knowledge during the workshop. To investigate the effects of stock-plant fertility on cutting production and rooting qualities of Iva imbricata, stock-plants were planted into one gal (3.8 L) containers. Plants were fertilized were fertilized with 5.5g, 11g, 15g, and 21g of Osmocote Plus (15N: 9P 2 O 5 : 12K 2 O; 8-9 month formulation at 21C [70F], Scott Miracle-Grow, Marysville, OH 43041), applied as a topdressing, per xii

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pot. Stock-plants were evaluated for shoot growth, total cutting production and rooting characteristics. In Experiment One stock-plant height and width increased as fertility rate increased for all harvests. The total fresh weight of cuttings and number of cuttings produced increased linearly with an increase in fertilizer rate for all harvests. Rooting response differed depending on the time of harvest. Percent rooting did not increase in response to an increase in fertility rate for any harvest period. Fertility rate had an effect on the number of roots per cutting that varied between harvests but did not influence root length. In Experiment Two fertility rate had no effect on stock-plant height and mean cutting weight, but stock-plant width and total fresh weight of cuttings increased as fertility rate increased. Total fresh weight of cuttings and cutting number increased linearly with an increase in fertilizer rate for all harvests. Increased fertility rate had a negative to neutral effect on percent rooting and mean root number but did not affect root length or cutting weight. High levels of fertility, which may be optimal for plant growth and cutting production, may have a negative effect on rooting percentages, root number and root length. Iva imbricata, Panicum amarum, and Schizachyrium maritimum were planted to examine the effect of intermixed composite plantings on transplant survival and sand accumulation. All planting combinations accumulated sand at a rate greater than bare sand controls. Intermixed composite plantings had a negative to neutral effect on plant survival and sand accumulation when compared to monoculture plantings. Plant density increased sand accumulation, however, survival of Schizachyrium maritimum decreased as plant density increased. xiii

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CHAPTER 1 INTRODUCTION Coastal dunes are found in almost all latitudes, but many are severely degraded by the exploitation of natural resources, chaotic demographic expansion, and industrial growth (Martinez and Psuty 2004). Coastal dunes exist in a dynamic environment often impacted by tropical storms that erode the shoreline and destroy foredunes (Ehrenfeld 1990). Loss of foredunes can result in storm surge washing over the breadth of the island damaging or destroying island ecosystems (Webb et al. 1997). Restoration of sand dunes is important for the protection of barrier island infrastructure and ecosystems from the further damaging effects of high tides, storm surges, and waves (Dahl et al. 1975). The recovery of barrier island vegetation aids dune building, island stabilization, and provides food and habitat for wildlife (Gore and Schaefer 1993, Snyder and Boss 2002, Swilling et al. 1998). The coastal dune ecosystem is complex and current restoration practices often do not reestablish that complexity. Changing restoration practices for coastal dunes requires public awareness and support. Garnering public support can be accomplished by extending knowledge gained through research to the public. Through outreach the importance of restoration of coastal dune systems can be conveyed and the need for inclusion of restoration in any successful plan to conserve these coastal systems can be supported. Before the use of any plant in restoration can become wide spread, production must be economical. Planting stock along with labor required for installation of plants 1

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2 represents one of the major costs of dune restoration and can vary widely by species (Woodhouse 1982). Plants suitable for wide use in restoration of coastal dunes must be economical to produce (Woodhouse 1982). By developing more efficient production practices for species such as Iva imbricata Walter [Asteraceae], planting stock costs can be reduced, which in turn will increase Iva imbricatas suitability for wide use in restoration projects. Research into plant-plant interactions and the dynamics that control sand movement and accumulation is key to development of effective restoration and management techniques for dune ecosystems. We examined interactions between three species of dune plants (Iva imbricata, Panicum amarum Ell. var. amarulum (A.S. Hitchc. & Chase) P.G. Palmer, and Schizachyrium maritimum (Chapman) Nash [Poaceae]) and the effect they have on sand movement and accumulation when planted on the beach. This research will increase the information available on how to effectively restore and manage coastal dune ecosystems.

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CHAPTER 2 DEMONSTRATION PLANTINGS AT NAVARRE BEACH (SANTA ROSA ISLAND, FL) In 1995, two major hurricanes impacted the Northwest Florida coast. Since these storms, local home and condominium owners, county governments and contractors have attempted dune restoration. However, government regulations designed to protect endangered sea turtles, such as the Leatherback (Dermochelys coriacea (Vandelli), limit or restrict the use of sand fence in the frontal dune position and create the need for restoration with plantings and without sand fence. Candidates for dune restoration include plants that are easily introduced, thrive in blowing sand, trap sand well, and are relatively free of pests. Restoration projects often rely heavily on Sea Oats (Uniola paniculata L. [Poaceae]) as it is the dominant grass of foredunes in the southeast (Woodhouse 1982). Although there are other plants that make substantial contributions to the geographical region, none are widely planted because they fail to meet one of the above criteria (Woodhouse 1982). In order to promote plant diversity and increase wildlife habitat, residents, contractors and local officials need exposure to the benefits of using more than one plant species in dune restoration projects. This is evident as 100% of calls to the Santa Rosa County extension office concerning dune plantings involved customers wanting information on how to plant only Sea Oats (personal communication C. Verlinde, September, 2003). Gulf Bluestem (Schizachyrium maritimum (Chapman) Nash [Poaceae]), Bitter Panic grass (Panicum amarum Ell. var. amarulum (A.S. Hitchc. & Chase) P.G. Palmer 3

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4 [Gramineae]), Sea Oats (Uniola paniculata), and Beach Elder (Iva imbricata Walter [Asteraceae]) are four western Gulf coast species commonly found in the frontal dune zone of barrier islands (Craig 1991). Two of these four coastal species (Beach Elder and Gulf Bluestem) have been the subject of propagation and production research and protocol development. Developed protocols were published to facilitate increased production of local populations of these coastal plants (Thetford and Miller 2004a, b). Although interactions among these four coastal dune species are not well understood, facilitation among plants in temperate and tropical dune systems has been documented (Franks 2003a, b, Martinez 2003). Facilitation between species in composite plantings may increase transplant survival and growth, rate of dune growth and diversity of plants available for wildlife. This project was aimed at achieving two goals. The first goal was to increase coastal awareness and stewardship. This was accomplished through an educational kiosk at the demonstration planting site, a brochure, and a website. In addition, a traveling program was developed for use at homeowner associations, civic organizations, planning board meetings and coastal workshops. The program included samples of recommended plants and a how to slide show. In addition, a survey was used at these meetings to gage pre and post program knowledge about plant diversity in dune restoration (Figure 1). The second goal was to gather preliminary data (plant height, plant width, plant survival) about dune plant interactions. Preliminary data was to be used to test and refine planting methods for use in a full-scale experiment planted the following summer. This data was not collected due to the loss of the plantings as a result of overwash from hurricane Ivan (16, September 2004). The objective of the full-scale experiment was to

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5 determine if composite plantings of Gulf Bluestem, Bitter Panic grass, Sea Oats and Beach Elder might facilitate dune formation in a frontal dune zone in the absence of fencing, and to examine the role facilitation and competition play in successful plant establishment. This project was completed through a series of partnerships between WFREC faculty, Santa Rosa County Sea Grant Extension Agent, Christina Verlinde, Escambia County Sea Grant Extension Agent, Andrew Diller and Okaloosa County Sea Grant Extension Agent, Scott Jackson M.S. graduate student Josiah Raymer and additional local stakeholders. Stakeholders included: Gulf Islands National Seashore, Santa Rosa County Board of County Commissioners, Navarre Beach Leaseholders Association, Santa Rosa County 4-H Youth, and the Pensacola Bay Area Environmental Education Coordination Team (with representatives from Florida Department of Environmental Protection, West Florida Regional Planning Council, University of West Florida, Northwest Florida Water Management District and additional civic and government organizations). The physical portion of the project (beach planting) was planted (17, May 2004) with the help of University of Florida staff, the Santa Rosa County Extension Office, and local 4-H volunteers. After which, deliverables for the project were developed. Deliverables produced for this project included a trifold brochure (Figures 2 and 3) and a Power Point presentation that were utilized by the extension service to educate the public about the project and issues affecting the dune ecosystem. A poster presented in a kiosk at the study site exposed beach visitors to the project and helped explain the purpose of the demonstration plots. Dune restoration signs donated by Santa Rosa County were placed at the demonstration site and a website containing all of the information about the

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6 project (pictures, plant information, trifold brochure, and power point presentation) was made available for anyone wishing to learn more ( http://wfrec.ifas.ufl.edu/extension/dunes ). This project aimed to educate the public about issues facing the dune ecosystem and how these issues affect them. Education of the public occurred when materials were presented at a variety of meetings, workshops, and events. These included 75 residents at two Navarre Beach Leaseholders Association meetings where the project was discussed and brochures were distributed. Additionally the project was presented to 15 participants of a Coastal Restoration Workshop where pre and post program surveys were completed by each participant. A poster was presented and brochures were distributed at several events including, Earthday at the Zoo April 2005 (100 people), Seagrass Awareness Festival March 2005 (200 people), and the Coastal Encounters event Oct. 2005 (300 people). Brochures were also distributed through a local eco-tourism business on the beach. The long-term impact of this project will be an increased awareness of some of the issues affecting barrier islands. Measurable impacts of the program were evident from the results of the preand post program tests administered at the Coastal Restoration Workshop. Among the 15 participants, 10 completed both preand post program tests. Results of the pretest indicated 100 percent of the participants were aware that dunes provide habitat for animals, protect the mainland from storms, and naturally undergo change (Table 1). The pretest also indicated that 100 percent of participants were aware that dunes are formed by sand that is trapped by plants. This high level of knowledge suggests many of the participants were highly knowledgeable about stewardship and the

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7 function sand dunes play in the coastal dune ecosystem (questions 1 and 2). Eighty percent of the participants also understood the concept of a monoculture suggesting that the participants were somewhat knowledgeable about concepts pertaining to plant diversity (question 3). This percentage did not increase in the post test and indicates that understanding of the concept of monoculture was not increased by the workshop. Only 30 percent of the participants knew about the basic flowering characteristics for Beach Elder prior to the workshop, and 60 percent knew about the basic flowering characteristics of Gulf Bluestem indicating that participants were less knowledgeable about individual plants that grow in the coastal dune system (questions 4 and 5). Knowledge about individual plants was increased by the workshop and was reflected in the increase in correct answers during the post test, which rose to 80 percent for Beach Elder and 70 percent for Gulf Bluestem. When post program test scores were compared to the pre program test scores there was a 16% difference in test scores. Ninety percent of the participants gained some knowledge during the workshop. An additional impact of this work was an increase in calls to the extension office asking where to get the plants described in the brochure and on the web site and how to volunteer for dune restoration projects. (personal communication C. Verlinde, October 2005). On September 19, 2004 Hurricane Ivan came ashore on Santa Rosa Island and destroyed the physical portion of the project (demonstration plantings and kiosks). The pamphlets, presentations, and website are still available and at this point there are plans to replant the study on Navarre Beach once renourishment efforts are completed.

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8 Please take a moment to fill out this survey before and after the Dune Restoration Presentation. The information will be used to determine whether we are meeting the goals of this program. Thanks in advance!!!!! Please circle your answers. 1. Why are dunes important? A. Provide habitat for birds, reptiles and mammals B. Protect the mainland and coastal development from storms C. Part of a natural changing environment of a barrier island D. All of the above 2. Dunes are formed when: A. It rains B. Mice live near them C. Sand is trapped among plants leaves, stems and roots D. When a sea turtle nests 3. A monoculture is: A. A single grain of sand B. Where only 1 species of plant is utilized (sea oat turf) C. An exotic plant D. None of the above 4. Which dune plant has small lavender flowers that occur in late summer? A. Gulf bluestem B. Bitter panicum C. Sea oats D. Beach elder 5. The seed head of this plant has dense silvery hairs. A. Bitter panicum B. Sea oats C. Gulf bluestem D. Beach elder Name_________________________________________ Figure 1. Preprogram and postprogram survey used to evaluate change in knowledge of coastal restoration workshop participants.

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9 Figure 2. Backside of Beachgoers Guide to Sand Dunes trifold brochure created for demonstration project.

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10 Figure 3. Frontside of Beachgoers Guide to Sand Dunes trifold brochure created for demonstration project.

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11 Table 1. Results of preprogram and postprogram survey taken by ten coastal restoration workshop participants. % of responses Question Response Preprogram Postprogram Difference Between Pre and Post Program Responses 1 A 100 100 0 B 0 0 0 C 0 0 0 D 0 0 0 2 A 0 0 0 B 0 0 0 C 100 100 0 D 0 0 0 3 A 0 0 0 B 80 80 0 C 0 10 10 D 20 10 -10 4 A 30 0 -30 B 10 20 10 C 0 0 0 D 30 80 50 5 A 20 20 0 B 0 10 10 C 60 70 10 D 0 0 0

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CHAPTER 3 EFFECT OF FERTILITY RATE ON CUTTING PRODUCTION OF STOCK-PLANTS OF IVA IMBRICATA: ROOTING CHARACTERISTICS OF CUTTINGS PRODUCED Introduction Seacoast Marshelder (Iva imbricata Walter [Asteraceae]) (hereafter referred to as Iva) is a dominant seashore plant and occurs on coastal dunes throughout the south Atlantic and Gulf region. Iva can spread vegetatively and by seed and is the only broad-leaved plant with a potential for building and stabilizing foredunes in the South Atlantic coast of the United States (Woodhouse 1982). Iva can grow throughout primary and most secondary successional zones and is occasionally found alone building foredunes but is usually found in combination with one or more dune grasses (Woodhouse 1982). Iva is used for dune restoration and stabilization projects (Craig 1991) and has also been identified as an important food for beach mice (Moyers 1996). Iva is a perennial C3 shrub (Franks 2003), which produces inflorescences at the tips of its stems in the fall. Iva has sparse woody stems from one to four feet (30 to 122 cm) tall with fleshy, narrow, lance shaped leaves. Highest rates of seed production on mature plants occur in foredunes while successful seedling establishment occurs in areas of little sand movement and favorable moisture (Woodhouse 1982) causing highest germination rates to occur on open beach or upper marsh in the spring (Colosi and McCormick 1978). Iva develops a strong system of rhizomes and roots when buried by soil and produces gently rounded dunes (Craig 1991). These growth characteristics make Iva desirable for dune restoration but the timing of seed production in natural regeneration may not 12

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13 provide sufficient plants for restoration and warrants development of efficient propagation and production practices for restoration efforts. Softwood cuttings of Iva stems root readily (Craig 1991) with rooting percentages greater than 90% achievable with or without auxin application for ten cm cuttings collected from native populations (Thetford and Miller 2002). Management of stock-plants in a nursery setting is desirable for producing a reliable and consistent source of cuttings. However, it is not presently known if container production of stock-plants for this purpose is a viable alternative or if stock-plant fertility may have an affect on cutting production, rooting percentage or the quantity or quality of the roots produced. Stock-plant nutritional fertility has been shown to be a factor in the rooting of softwood and hardwood cuttings (Blazich 1988, Veierskov 1988). For example cuttings of Pelargonium sp (Geranium) harvested from stock-plants grown under low and medium fertility rates (N, P, K) demonstrated an increase in rooting percentage when compared to high fertility rates (Haun and Cornell 1951, Blazich 1988, Veierskov 1988). A similar response was noted by Preston et al. (1953) when propagating Rhododendron sp. (Azalea) maintained under similar fertility rates where low and medium rates demonstrated higher rooting percentages than high fertility rates. Optimum stock-plant nitrogen levels for rooting of cuttings has also been shown to occur below the optimum level for stock-plant growth for Juniperus virginiana L. (Eastern Red Cedar) where optimum growth occurred at 100-150 mg/L N while optimum rooting occurred at 20-40 mg/L N (Henry et al. 1992). This previous work demonstrates a need to consider not only the effects of fertilization on the number of cuttings produced, but to also consider the effects of stock-plant fertility on the rooting success of cuttings when optimizing

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14 stock-plant fertility rates. Finding an acceptable level of stock-plant fertility to maximize cutting production without sacrificing root quality will lead to better management practices. The objective of the following experiments was to investigate the affects of stock-plant fertility on cutting production and evaluate the rooting qualities of harvested cuttings. Materials and Methods Forty-eight stock-plants of Iva were planted on both 3 February, 2004 (Experiment One) and 9 July, 2004 (Experiment Two) using eight cm liners transplanted into one gal. (3.8 L) containers. Liners were grown in a pine bark substrate amended with six lbs. (2.7 kg) dolomitic limestone per yd 3 (0.76 m 3 ). Plants were pruned to eight cm in height seven days after planting (DAP). Osmocote Plus (15N: 9P 2 O 5 : 12K 2 O; 8-9 month formulation at 21C [70F], Scott Miracle-Grow, Marysville, OH 43041) was applied as a top dressing at 5.5 g, 11 g, 15 g, and 21 g per pot with 11 g representing the recommended fertility rate for a one gallon plant. Plants were grown in full sun receiving 30 min of overhead irrigation twice daily. The experiment was a completely randomized design consisting of four fertility treatments with 12 single-plant replications. Experiment One was initiated using dormant liners while Experiment Two was initiated during the growing season. First harvest was conducted when all of the stock-plants in the experiment had sufficient growth to collect at least four 10 cm cuttings. The first harvest of cuttings from each experiment began 114 and 49 DAP respectively. Stock-plants were evaluated for shoot growth (stock-plant height and width) and total cutting production at each of 4 harvest dates [114,146, 175, and 206 DAP for Experiment One and 49, 79, 108, and 136 DAP for Experiment Two.]. Each plant was measured for

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15 maximum shoot height and width (mean of two perpendicular widths) and all tip cuttings 10 cm in length harvested. The total number and total weight (g) of cuttings collected from each plant was recorded and the stock-plants were cut back to a height of 20 cm. Rooting characteristics of cuttings were quantified utilizing a sub-sample of four cuttings randomly selected from the pool of cuttings taken from each stock-plant at each harvest. Cutting were stripped of leaves two cm above the base and a fresh cut made prior to treatment with Hormodin-1, 1000 mg/L IBA (indole-3-butyric acid) auxin rooting powder (OHP, Inc., Mainland, PA 19451). Each rooting experiment contained four cuttings from each of the 12 stock-plants representing each of the four fertilizer treatments for a total of 192 cuttings. However, the first harvest of Experiment Two did not yield sufficient cuttings so no rooting data are available for that date. All rooting experiments were arranged in a randomized complete block design with each of the 12 blocks containing 16 cuttings. Bench position was used as a blocking factor to account for differences in environmental conditions along the length of the greenhouse bench. Cuttings were inserted two cm deep into 72 cell plug flats filled with Fafard #4M Mix (40% peat, 35% vermiculite, 25% bark) ( Conrad Fafard, Inc., Agawam, MA 01001) Cuttings were randomly placed under intermittent mist operating at four seconds of mist every ten min from 7:00 A.M. to 8:00 P.M. with bottom heat of 80F. Cuttings were evaluated for rooting 14 days after sticking and the roots washed free of propagation substrate. Root number (primary roots emerging from the cutting) and length of the longest root (cm) were recorded for each cutting. Mean fresh weight of cuttings was calculated for each stock-plant using total fresh weight of all cuttings harvested divided by total number of cuttings harvested. A plant

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16 growth index was calculated for each stock-plant using plant height and width ((mean width + ht)/2) to evaluate the combined effects of changes in height and width and monitor overall changes in plant growth form. Rooting percentage was calculated based on the number of cuttings rooted from each stock-plant. An estimate of total root length was calculated as the product of root number and root length to estimate the combined effects of root number and root length. Data were analyzed for treatment affects using the general linear models procedure of SAS (SAS Institute Inc. 2000-2004). Results and Discussion Stock-plant growth and cutting production were influenced by the rate of fertilizer applied but responses were not consistent across harvest times or between the two experiments. This trend was also true for rooting percentage and measures of root quality. The two experiments had differing responses, which were thought to be a result of seasonal growth effects associated with the timing of the two experiments. Hence, data for the two experiments are presented separately. Experiment One Stock-plant growth and cutting production The main effects of fertility and harvest both had a significant effect on stock-plant size as shown by changes in height, width and growth index (Table 1). There were significant interactions between the effects of fertility and harvest for all variables except stock-plant width. Pearson correlation coefficients indicate stock-plant height and width were not correlated although both were highly correlated with growth index (r = 0.858 and 0.816 respectively).

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17 Stock-plant height increased as fertility rate increased for all harvests (Figure 1). There was a significant decrease in stock-plant height for all harvest periods when fertility rate decreased to 5.5 g, a rate representing half the recommended rate of 11 g. Prior to the first harvest of cuttings plant height followed a classic fertilizer growth response curve and maximum height was achieved between the rates of 11 g and 15 g. However, after first harvest plant height did not differ between the 11 g, 15 g, and 21 g fertilizer rate. Stock-plant width increased as fertility rate increased for all harvests (Figure 2). There was a significant decrease in stock-plant width for all harvest periods when fertility rate decreased to 5.5 g. Plant width did not differ between the 11 g and 15 g, however, and there was a significant increase in plant width when the fertility rate was increased to the 2-times recommended rate of 21 g when compared to the recommended rate. Fertilizer rate had a significant effect on stock-plant growth index resulting in an increase in plant growth index as fertilizer rate increased (Figure 3). This response was particularly evident prior to the first harvest of cuttings when the greatest differences in stock-plant size were evident and followed a classic quadratic fertilizer growth response curve (Figure 3). When fertilizer was applied at half the recommended rate of 11 g there was a 35% decrease in plant growth index while fertilizer applied at twice the recommended rate of 11 g resulted in a 13% increase in plant growth index. After the initial harvest of cuttings plant growth index did not differ among plants fertilized with 11 and 15 g of Osmocote. The data suggests nearly a 2x application of the recommended rate is necessary to affect a significant increase in plant growth index for Iva stock-plants.

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18 Although hedging of stock-plants reduced height to 20 cm following each successive harvest of cuttings, stock-plant growth index (Figure 1) increased with each successive harvest (P < 0.0001). The effects of increasing stock-plant width resulted in a 5% increase in growth index from harvest one to the harvest four. Fertility rate as well as time of harvest had a significant effect on the total fresh weight of cuttings removed from each plant (P < 0.0001, Table 2). The total fresh weight of cuttings increased linearly with an increase in fertilizer rate for all harvests (Figure 4). Total fresh weight of cuttings decreased 35% from harvest one to harvest three before increasing 27% from harvest three to harvest four for the 11 g rate. Fertility rate had a significant effect on cutting number (P < 0.0001). The number of cuttings produced per stock-plant increased linearly with increasing rate of fertility for all harvests (Figure 5). The number of cuttings produced at the recommended rate per stock-plant increased with each successive harvest (P < 0.0001), resulting in an increase of 93% from harvest one to harvest four (Figure 5). Pearson correlation coefficients indicate that the number of cuttings produced was not correlated with plant height (r = 0.2539) or index (r = 0.5733) but was highly correlated with plant width (r = 0.74923) across harvests. This suggests stock-plant width has a greater positive effect on increases in cutting production than stock-plant height and that managing stock-plants in a fashion that increases width will result in an increase in cutting production. Fertility rate as well as time of harvest had a significant effect on individual cutting weight (P < 0.0001). The weight of individual cuttings increased linearly with an increase in fertilizer rate for harvests one and two (Figure 5). Cutting weight was 53-56% greater at harvest one than at other harvests when averaged across fertility rates

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19 (Figure 6). At the time of the first and second harvests, cutting weight increased 24% and 10% with a doubling of the fertility while cutting weight did not differ at 2x the recommended rate at the third and fourth harvests. Rooting percentages and quality The main effects of fertility and time of harvest were significant for most measured rooting variables (Table 3). An interaction was present between the main effects of fertility and time of harvest for all measured variables indicating the rooting response differed depending on the time of harvest. Percent rooting was influenced by fertility rate (P = 0.0035) and the time of harvest (P < 0.0001) (Figure 7). Percent rooting did not increase in response to an increase in fertility rate for any harvest period. Harvests one and four had rooting percentages between 88% and 100% for all fertility levels. Rooting percentages for harvest period two declined linearly as fertility level increased and ranged from 79% at the lowest rate to 54% at the highest rate. Rooting percentages for harvest period three declined linearly as fertility level increased and ranged from 63% at the lowest rate to 35% for the highest rate. Increasing fertility rate of I. imbricata stock-plants does not increase the rooting percentage of harvested cuttings. Fertility rate had a significant effect on the number of roots per cutting (P = 0.016) but did not influence root length (P = 0.0772) (Figures 8 and 9). During harvest period one root number declined linearly as fertility rate increased and ranged from 8.6 roots per cutting at the lowest rate to 6.3 roots per cutting at the highest rate. Root number did not differ in response to fertility rate for harvests two through four with 4.3 to 6.9 roots produced per cutting.

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20 Fertility rate as well as time of harvest had a significant effect on root index (P = 0.0151 and P < 0.0001)(Table 3). Root index decreased linearly as fertility rate increased for harvest one (Figure 10). Root index then began to increase linearly as fertility rate increased for harvest four. Experiment Two Stock-plant growth and cutting production The main effects of fertility and time of harvest both had a significant effect on stock-plant width and growth index but did not have a significant effect on stock-plant height (Table 1). There were no significant interactions between the effects of fertility and harvest for height, width or growth index (Table 1). Pearson correlation coefficients indicate stock-plant height and width were not correlated although width was highly correlated with growth index (r = 0.7803). Fertility rate had no effect on stock-plant height (Figure 11) but decreases in stock-plant height following each harvest of cuttings indicate plant regrowth was affected by the time of harvest (P < 0.0001). Stock-plant fertility did have a significant effect (P < 0.0001) on stock-plant width (Figure 12). Compared to the standard rate of 11 g, there was a significant decrease in stock-plant width for all harvest periods when fertility rate decreased to 5.5 g. Stock-plant width at the 5.5 g rate of fertilizer remained nearly constant following each successive harvest of cuttings. Stock-plant width increased with each subsequent harvest of cuttings when fertilizer was applied at the recommended rate or greater. However, stock-plant width did not differ among plants fertilized at 11 g, 15 g, or 21 g rates. Fertility rate (P < 0.0001) and time of harvest (P =0.0004) both had a significant effect on plant growth index. Plant growth index demonstrated a linear or quadratic

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21 increase as fertilizer rate increased. The greatest increase in plant index occurred from 5.5 g to 11 g and no significant increase in plant index was evident when the fertilizer rate was doubled to 21 g. (Figure 13). The data suggest that even a 2x fertility rate does not increase stock-plant growth index compared to the recommended rate. Fertility rate as well as time of harvest had a significant effect on the total fresh weight of cuttings removed from each plant (P < 0.0001)(Table 2). The total fresh weight of cuttings increased linearly with an increase in fertilizer rate for all harvests (Figure 14). Total fresh weight of cuttings increased 178% from harvest one to harvest four for the 11 g rate. Total fresh weight of cuttings decreased 23% from harvest two to harvest three causing an interaction between fertilizer rate and harvest period. Fertility rate (P < 0.0001) had a significant effect on the number of cuttings harvested. Cutting number increased linearly as fertility rate increased (Figure 15). Reducing the fertilizer rate to 5.5 g resulted in a 29% to 48% decrease in cutting production. However, increasing the fertilizer rate above 11 g did not increase the number of cuttings produced per plant. Cutting number also differed with the time of harvest (P < 0.0001). Cutting number began to increase by the third harvest of cuttings and then began to decrease at the fourth harvest. Fertility rate did not have a significant effect on mean cutting weight (P = 0.3750) but cutting weight did increase from harvest one to harvest four (P < 0.0001)(Figure 16). Rooting percentages and quality The main effects of fertility and time of harvest were significant for most rooting variables (Table 3). An interaction was also present between the main effects of fertility and harvest for all rooting variables indicating the rooting response differed depending on the time of harvest.

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22 Percent rooting was influenced by fertility rate (P = 0.0269) and the time of harvest (P < 0.0001) (Figure 17). Rooting percentages for cuttings collected during harvest two remained above 90% regardless of the level of stock-plant fertility. However, at subsequent harvests, rooting percentages began to decrease for cuttings taken from plants receiving less that 21 g of fertilizer. At harvest three rooting percentages indicate a linear increase as the rate of stock-plant fertility increased resulting in a 28% decrease in rooting percentage from the 21 g rate to the 5.5 g rate. Rooting percentages further decreased as fertility rate decreased at harvest four and ranged from 64% to 83%. Both fertility rate (P = 0.0059) and time of harvest (P < 0.0001) had a significant effect on mean root number (Table 3). At harvest two the number of roots per cutting initially increased as stock-plant fertilizer rate increased but this trend became reversed by the fourth harvest (Figure 18). The number of roots per cutting for harvest period two was 21% to 63% higher than root number for subsequent harvests. Root number per cutting decreased through harvest period four and cuttings from stock-plants fertilized at 11 g had 5.2 roots per cutting by harvest four. Mean root length was not affected by the rate of stock-plant fertilizer treatment (P = 0.2079), however root length did differ with the time of harvest (P < 0.0001). Root length was significantly higher during harvest two compared to subsequent harvests (Figure 19). Root length decreased from 10 to 12 roots per cutting at harvests two to only two roots per cutting at harvest four. The similar decreases in root number and root length are also reflected in the root index (Figure 20). The effects of stock-plant fertility and time of cutting harvest on root index resembles the response of root number more than root length.

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23 Fertility rate as well as time of harvest had a significant effect on root index (P = 0.0008 and P < .0001)(Table 3). Root index increased linearly as fertility rate increased for harvest two but had no effect for harvests three and four (Figure 20). Root index was 286% to 913% higher at harvest two than at harvests three and four showing a dramatic reduction in root index from period two to four. Discussion The effect of fertility rate on plant growth before the first harvest of cuttings from both Experiments one and two exhibited a classic growth response curve in response to an increase in fertilizer rate (Figures 3 and 13). In both experiments, the greatest increase in growth occurred when the rate of Osmocote increased from the 5.5 g to 11 g. The rate of growth slowed but continued to show an increase when the rate of Osmocote increased from 11 g to 15 g. Iva growth rate did not increase when the rate of Osmocote was increased from 15 g to 21 g. This trend was exhibited for both plant height and plant width (Figures 1, 2, 11, and 12). These results indicate the growth rate of Iva can be increased with the application of Osmocote up to the 15 g rate but no additional benefit in growth can be achieved with further increases in the rate of fertilization. Maximizing plant growth with the application of 11 to 15 g of Osmocote will allow for shorter grow out times in a nursery production system, which will in turn increase the numbers of plants that can be produced in a given time period while reducing production costs. After the first harvest of cuttings for both experiments, increases in plant height in response to fertilizer slowed while plant width continued to increase in response to an increase in fertility rate. In addition, width also increased with each successive harvest and was highly correlated with an increase in the number of cuttings produced. Cutting production has also been shown to increase with successive harvests in Antirrhinum,

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24 Chrysocephalum, Diascia, Lavendula, Osteospermum, and Verbena in response to hedging. This shows that hedging stock-plants results in an increase in cutting number (Faust and Grimes 2005). Faust and Grimes (2005) also found that increasing the hedging height in successive harvests maximized cutting production. Iva stock-plants were hedged to a constant height in our experiments but further increases in the number of cuttings produced may have been realized with successive increases in stock-plant height following each successive harvest. Over a 23 week period cutting quantity and quality of Scaevola cuttings has been shown to increase over time as N fertilization concentration increased from 100 to 300 mg / L (Gibson 2003). Similarly, stock-plants of Pelargonium sp. have been shown to produce low numbers of cuttings at a 50 mg/L rate while producing higher numbers of cuttings at the 100 mg/L, 200 mg/L, and 400 mg/L rates (Ganmore-Neuman and Hagiladi 1990, 1992). The strong correlation in Experiment One and weak correlation in Experiment Two between the increase in stock-plant width and the increase in cutting production suggests that managing stock-plants in a manner that increases width will also cause cutting production to increase as fertility level increases. But, similar to plant growth, cutting number did not continue to increase as fertilizer rates were increased above the 15.0 g rate. Time of harvest had a stronger influence on the weight of individual cuttings than did the rater of fertilizer. When cutting weight is graphed across time (Figure 21) the lowest weights per cutting were evident during the months of June and July and correspond with the period of lowest rooting percentages. Seasonal effects on cutting production and quality have been reported for many crops such as Pelargonium sp. and

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25 Cotinus coggygria (Ganmore-Neuman and Hagiladi 1992, Cameron et al. 2005). Work by (Ganmore-Neumann et al. 1992), showed that low irradiance levels during stock-plant growth caused a drop in cutting production while causing an increase in rooting characteristics. Cameron et al. (2005) showed that rooting percentages responded to changes in photoperiod differently according to season. Rooting of cuttings harvested in August were unaffected by short day compared to long day photoperiod while cuttings harvested in September had higher levels of rooting in the long day photoperiod. Changes in light characteristics may have been a factor in the seasonal effect on rooting percentages of cuttings taken from Iva stock-plants. Stock-plant nutrition has been shown to have a significant effect on rooting percentages (Blazich 1988, Veierskov 1988), as was observed in this study. Rooting percentage had an inverse relationship with fertility rate from May through July suggesting that high levels of fertility should be avoided during that period to keep from negatively affecting rooting percentages. High levels of fertility, which may be optimal for plant growth and cutting production, had a negative affect on rooting percentages, root number and root length. This inverse relationship has also been demonstrated in cuttings taken from stock-plants of Pelargonium sp, Rhododendron sp, and Eastern Redcedar (Haun and Cornell 1951, Preston et al. 1953, Henry et al. 1992). Haun et al (1951), Preston et al (1953), and Henry et al (1992) all found inverse relationships between stock-plant fertilization and rooting percentages in cuttings harvested from stock-plants. With Iva this trend was not consistent throughout the season. Higher fertilizer rates had a neutral to positive effect on Iva rooting percentage and quality

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26 during the months of August through November. This may be a result of the onset of flowering in Iva, which is fall flowering, or the onset of dormancy. The recommended rate of 11.0 g of Osmocote Plus per one-gallon pot produced nearly maximum plant growth and resulted in acceptable rooting percentages throughout the growing season. Optimum rooting percentages occurred from May to early June and August through September, suggesting two optimum harvest periods. Utilizing a stock-plant hedging technique was a successful method for the production of Iva cuttings. Propagators should prune stock-plants to maximize plant width during spring and schedule a harvest of cuttings from May to early June. After this initial harvest of cuttings stock-plants may benefit from a period of growth when rooting percentages are minimal. By scheduling a second harvest during August through September, cutting production will be maximized and cuttings will be propagated at a time when cuttings root at a high percentage. Avoiding harvest and propagation of cuttings when rooting percentages will be at their lowest will improve propagation success and increase production efficiency.

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27 2025303540450510152025Fertility Rate (g)Height (cm) Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 4. Plant height by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. 10152025300510152025Fertility Rate (g)Width (cm) Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 5. Plant width by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.

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28 15202530350510152025Fertility Rate (g)Index Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 6. Plant growth index ((mean width + ht)/2) by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. 051015202530354045500510152025Fertility Rate (g)Fresh Weight (g) Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 7. Total fresh weight cuttings by fertility rate and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.

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29 051015202530350510152025Fertility Rate (g)Cutting Number Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 8. Cutting number produced by fertility rate and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) utting weight by fertility rate and month of ha per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. Figure 9. Crvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one0.51.01.52.02.53.00510152025Fertility Rate (g)Cutting Weight (g) Harvest 1 Harvest 2 Harvest 3 Harvest 4 gallon pot, 5.5, 11.0, 15.0, and 21.0.

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30 304050607080901000510152025Fertility Rate (g)% Rooting Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 10. Percent rooting by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. 2468101214160510152025Fertility Rate (g)Root # Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 11. Root number by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.

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31 024681012140510152025Fertility Rate (g)Length cm Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 12. Root length by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. 0204060801000510152025Fertility Rate (g)Index Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 13. Root index by fertility rate, and month of harvest for Experiment One. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.

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32 2025303540450510152025Fertility Rate (g)Height (cm) Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 14. Plant height by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. 10152025300510152025Fertility Rate (g)Width (cm) Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 15. Plant width by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.

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33 15202530350510152025Fertility Rate (g)Index (cm) Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 16. Plant growth index ((mean width + ht)/2) by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. 051015200510152025Fertility Rate (g)Fresh Weight (g) Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 17. Total fresh weight cuttings by fertility rate and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.

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34 051015202530350510152025Fertility Rate (g)Cutting Number Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 18. Cutting number produced by fertility rate and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. 0.51.01.52.02.53.00510152025Fertility Rate (g)Mean Cutting Weight (g) Harvest 1 Harvest 2 Harvest 3 Harvest 4 Figure 19. Cutting weight by fertility rate and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.

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35 304050607080901000510152025Fertility Rate (g)% Rooting Harvest 2 Harvest 3 Harvest 4 Figure 20. Percent rooting by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. 2468101214160510152025Fertility Rate (g)Root # Harvest 2 Harvest 3 Harvest 4 Figure 21. Root number by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.

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36 024681012140510152025Fertility Rate (g)Length cm Harvest 2 Harvest 3 Harvest 4 Figure 22. Root length by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0. 0204060801001201401601802000510152025Fertility Rate (g)Index Harvest 2 Harvest 3 Harvest 4 Figure 23. Root index by fertility rate, and month of harvest for Experiment Two. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month at 70F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.

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37 Figure 24. Mean fresh weight of cuttings by run, fertility rate, and month of harvest. Exp1 = Experiment 1, Exp2 = Experiment 2. Fertility rate in grams of Osmocote Plus (15-9-12, 8-9 month @ 70 F) per one-gallon pot, 5.5, 11.0, 15.0, and 21.0.

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38 Table 2. Main effects by measured variable and experiment for total fresh weight cuttings, number of cuttings produced, and fresh weight of individual cuttings.

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39 Table 3. Main effects by measured variable and experiment for mean percent rooting, root number, root length, and root index (root number root length).

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CHAPTER 4 RESTORATION OF FOREDUNES WITH INTERMIXED COMPOSITE PLANTINGS Introduction Tropical cyclones can cause extensive damage to coastal ecosystems. Foredunes, the primary barrier to the damaging effects of storm surge on inland areas, absorb the brunt of these storms. Storm surge and attending waves often result in partial to complete destruction of foredunes creating a need for dune restoration. Dune restoration projects along the Southeast coast of the United States often plant monocultures of Uniola paniculata L. [Poaceae](Sea Oats) to restore foredunes. Uniola paniculata is the dominant grass naturally occurring on foredunes along the southeast coast of the United States (Dahl et al. 1977, Woodhouse 1978). This grass forms a dense latticework of rhizomes and tillers, which trap sand and stabilize forming dunes (Clewell 1986). U. paniculata is planted because it tolerates salt spray, sand accumulation, drought, and because of its dune stabilizing characteristics (Woodhouse et al. 1968, Clewell 1986). However, multiple species plantings or intermixed composite plantings may be beneficial because of potential positive interactions or facilitation among dune plants. Also, planting more than one species increases the diversity of plants available for wildlife. Schizachyrium maritimum (Chapman) Nash [Poaceae]) (Gulf Bluestem), Panicum amarum Ell. var. amarulum (A.S. Hitchc. & Chase) P.G. Palmer (Bitter Panic Grass), and Iva imbricata Walter [Asteraceae] (Seacoast Marshelder) are three additional western 40

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41 Gulf coast species commonly found on coastal dunes (Craig 1991), which are sometimes used in restoration projects. Schizachyrium maritimum is considered the most important species of bluestem grass on the Gulf of Mexico and occurs primarily on dunes, beaches, and coastal swales (Craig 1991). It is a perennial, short, dense, stoloniferous grass (Johnson 1997). The plants prostrate growth habit makes it effective at trapping sand. S. maritimum is often dominant in coastal dunes (Clewell 1986) and naturally replaces U. paniculata as soon as a foredune ridge develops (Johnson 1997) making it a good candidate for beach projects requiring planting on the backside of a primary dune and all sides of secondary dunes. Panicum amarum is a perennial, warm season grass that occurs on coastal dunes throughout the gulf coast. Although outcompeted by U. paniculata, P. amarum remains a part of the permanent vegetation cover along the southeastern coast (Seneca et al. 1976, Woodhouse 1978). P. amarum grows to heights of up to 213 cm and has large wide leaves. Plantings of P. amarum are less affective at accumulating sand when compared to U. paniculata and Ammophila breviligulata (Fernald) (American Beachgrass) or when planted in combination with those species. However, P. amarum provides more groundcover than U. paniculata or A. breviligulata during the same period of establishment, which suggests its principal value may be in stabilizing sandy coastal areas and developing foredunes (Seneca et al. 1976). Iva imbricata occurs on coastal dunes throughout the gulf coast and is used for dune restoration and stabilization projects (Craig 1991). The plant has sparse, woody, upright stems and fleshy, narrow leaves. It is prized for its ability to accumulate sand and

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42 produce low, rounded dunes. Both I. imbricata and S. maritimum have been identified as important beach mice foods (Moyers 1996). Sand accumulation resulting from aeolian movement of dry sand on beaches is a major environmental factor effecting plant survival and growth. Burial is a strong selective force and can alter the composition of plant communities (Martinez and Psuty 2004). Plant species differ in how they respond to sand accumulation. Species tolerant of burial usually have an extensive system of both vertical stems and horizontal rhizomes (Ehrenfeld 1990). Plant response to burial changes from positive to negative at a species threshold level of burial (Martinez and Psuty 2004). Foredunes species such as U. paniculata respond to sand accumulation below burial threshold by increasing photosynthetic rate (Yuan et al. 1993), which stimulates growth (Clewell 1986). This allows the plant to extend above the level of sand accumulation and survive. However, if sand accumulation exceeds a species burial threshold then the plant is stressed, which can lead to death. Sand accumulation also can prevent seed germination and establishment if burial is too deep (Sykes and Wilson 1990). The stimulatory response is the most common response of dune species to burial (Maun and Baye 1989). Plant-plant interactions can be competitive, neutral, or facilitative. Facilitation in plant communities occurs when a plant changes the conditions experienced by another plant resulting in benefit to one of the plants or benefit to both (mutualism) and causing harm to neither (Odum 1953). Facilitation may result when plants increase the nutrient content of the soil, increase soil moisture by shading the surface, reduce evaporation, block salt spray, increase soil stability and/or reduce herbivory or seed predation (Franks 2003b). Competition occurs when plants compete for resources to the benefit of one

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43 plant at the expense of another. The idea that positive as well as negative or neutral interactions may be fundamental processes in plant communities (Hunter and Aarssen 1988, Bertness and Callaway 1994, Callaway 1995) is gaining wide acceptance. Succession refers to the changes observed in an ecological community following a disturbance that opens up a relatively large space (Connell and Slatyer 1977). Interspecific interactions between plants and the effect they have on local abiotic conditions are a major force driving succession in some ecosystems (Clements et al. 1916). Facilitation is likely more important than competition in the very early stages of succession (Bertness and Callaway 1994, Goldberg et al. 1999). Reaction theory (Clements et al. 1916, Connell and Slayter 1977) suggests that the reaction of the environment to plants modifies the environment so that previously excluded plants can invade. Building on this early successional theory, the nucleated succession model suggests early colonizing plants establish in barren areas and alter the environment as they grow. These colonizers act as nurse plants (Niering et al. 1963) which facilitate the establishment of late successional species (Franks 2003b). As environmental conditions are altered and mid and late successional species become established, competition may replace facilitation as the dominant mechanism affecting species competition. Successional endpoints however are not uniform and can change in response to xeric conditions, salt spray, periodic overwash and windblown sand (Snyder and Boss 2002) resulting in changes in species dominance at different locations. Knowledge about the stages of succession and what role facilitation plays in it could provide valuable information about succession of coastal ecosystems.

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44 Experiments documenting facilitation have been conducted in many diverse ecological systems such as the Sonoran Desert, New England salt marsh, old Saskatchewan agriculture field sites, South African shrub lands, sub arctic coastal dunes, temperate coastal dunes, and tropical coastal dunes (Niering et al. 1963, Bertness 1991, Bertness and Hacker 1994, Li and Wilson 1998, De Villiers et al. 2001, Gagne and Houle 2001, Franks and Peterson 2003, Martinez 2003, Rudgers and Maron 2003). Facilitation among plants has been shown to increase in frequency as environmental stress increases (Callaway and Walker 1997, Maestre and Cortina 2004). Thus, facilitation may play an important role in the succession of coastal foredunes, as it is a highly stressful environment. Knowledge about how plant species interact with each other could prove to be valuable in dune restoration. Interactions between plants may positively effect plant survival but negatively affect plant growth (Franks 2003a), suggesting that interactions may be even more complex with both facilitation and competition occurring at the same time through different mechanisms. In addition, the balance between competitive and facilitative interactions between plants can be affected by the life stage of the plant or as the environment they interact with is modified (Kellman and Kading 1992, Pugnaire et al. 1996, Callaway and Walker 1997). It has also been shown that facilitative and competitive mechanisms do not act independently of each other and can occur within the same community and even the same individual (Callaway and Walker 1997). With such complex interactions occurring a thorough understanding of the coastal dune systems ecology and the physiology of the plants found in it will be necessary before we can truly understand the different aspects of how plants are interacting.

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45 Interactions among I. imbricata, S. maritimum and P. amarum are not well understood although U. paniculata seedling establishment has been found to increase when seeds germinate within the canopy of established I. imbricata plants (Franks 2003a). Facilitation among Chamaecrista chameacristoides (L.) and two late colonizing grasses, (Schizachyrium scoparium (Michx.) Nash and Trachypogon plumosus (Humb. & Bonpl. ex Willd.)) in tropical dune systems along the SE coast of the Gulf of Mexico has also been documented (Martinez 2003). The objective of this experiment was to compare sand accumulation rates and survival of monocultures and composite plantings of I. imbricata, P. amarum, and S. maritimum at two plant densities. We asked the following questions. Does plant density affect the survival of individual species? Does planting combination affect survival of individual species? Does plant density affect sand accumulation rates for individual species? Does planting combination affect sand accumulation rates? Does sand accumulation have an effect on survival of individual species? Answering these questions will help to determine if facilitation or competition between species is occurring and what effect planting combinations have on sand accumulation and transplant survival. This information can be used to develop efficient methods for restoring dunes using plant combinations that provide for rapid sand accumulation and maximum survival of all three species. Study Site This study was conducted on Santa Rosa Island, Florida (30 18 N, 87 16 W), a Holocene barrier island consisting of almost 100% pure quartz sand (median diameter of 0.25 mm). Study sites were located on two nearly undeveloped sections of the island,

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46 which are part of Eglin Air Force Base (Figure 25). The island, part of the western panhandle of Florida, has historically been one of the most stable shorelines along the Gulf Coast (Otvos 1982, Morton et al. 2005, Otvos 2005). However, in 1995 two major hurricanes (Erin and Opal) impacted the Northwest Florida coast. These storms caused extensive beach erosion and leveled a majority of the established frontal dunes. Following a 9-year period of dune growth, Northwest Florida was hit by another major hurricane, (Ivan), in September 2004, which caused further erosion or loss of remaining established foredunes and flattened incipient foredunes. The climate of Santa Rosa island is subtropical with 152 cm mean annual precipitation and rainfall peaks in summer and late winter/early spring. Northerly winds prevail from September-February with southerly winds the rest of the year. Highest monthly wind speeds occur during fall, winter, and spring (Miller et al. 2001). Methods Experimental Design This experiment followed a randomized complete block design arranged as a split plot with sites as blocks, density allocated to main plots and planting combinations allocated to subplots. Six sites, each approximately 80 m from mean high tide line where overwash associated with hurricane Ivans (16 September, 2004) 5 m (15 ft) storm surge removed perennial vegetation and frontal dune elevation, were randomly chosen from available overwash sites to serve as blocks and replicates. On Jan. 27-30 2005, Schizachyrium maritimum, Panicum amarum, and Iva imbricata, were planted in 0.6 x .9 m or 0.9 x 1.35 m subplots either 30 cm (12 in) or 44 cm (18 in) apart (density treatments) respectively in 8 planting combinations (combination treatments) for a total of 16 treatments. The total number of plants per combination treatment was held

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47 constant at 12 with a random placement of each plant within the 3 rows of 4 plants running parallel to the shoreline. Three of the combination treatments consisted of 12 plants of the same species (monoculture), three consisted of six plants each of two different species (biculture), one consisted of four plants each of three different species (triculture), and a control (no plants). Plants were beach planted with the top of the root ball placed approximately 5 cm below the surface without root scoring, supplemental watering, or fertilizer. Data Collection Base line and sand accumulation (change in height (cm)) at the center of each combination treatment was measured with a laser transit at 0, 33, and 117 days after planting (DAP), January 27, February 1, and May 24 respectively. Accumulation levels were calculated for three periods 0-33 DAP (period one), 33-117 DAP (period two), and Total sand accumulation. Survival was recorded as the presence of any living shoot visible above the sand at 130 DAP. Total survival was determined for each subplot to determine plant density. To determine differences in survival of each species among treatments, a random subset of four plants per species from each treatment was used to standardize n. Analysis Data was subjected to Proc Mixed Procedure of SAS to perform a repeated measures analysis of variance (SAS Institute Inc. 2000-2004). Contrast statements were used to determine significant differences between planting combinations. Significance of main effects for survival was determined using the Proc Genmod procedure of SAS (SAS Institute Inc. 2000-2004).

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48 Results Sand Accumulation Sand accumulated significantly more than bare sand controls in all planting combinations during the first 33 DAP (Table 4). All planting combinations except S. maritimum monocultures continued to gain significant amounts of sand for the remainder of the measurement period. Effects of planting combination and spacing on sand accumulation were significant. There was no significant interaction between spacing and planting combination. Total mean sand accumulation for P. amarum planted in monoculture was significantly higher than when planted in combination with another species. Mean accumulation for I. imbricata planted in monoculture did not differ significantly from mean accumulation when planted in combination with another species for any accumulation period. S. maritimum planted in monoculture had significantly higher mean accumulation than when planted in combination with other species for the first 33 DAP but had significantly lower mean accumulation for period two and Total accumulation. Mean sand accumulation was significantly higher (P = 0.0239) for 30 cm spacing compared to 44 cm spacing 33 DAP but did not differ significantly (P = 0.8109) between spacing treatments during period two. Total mean accumulation was significantly higher (P = 0.0038) at 30 cm compared to 44 cm spacing. Monoculture plantings of P. amarum had a significantly higher mean sand accumulation than biculture plantings during all periods while monoculture plantings of I. imbricata did not have significantly different mean accumulation when compared to biculture plantings for all periods. Monoculture plantings of S. maritimum had

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49 significantly higher accumulation rates than biculture plantings 33 DPA. However, accumulation was significantly lower for period two and Total accumulation. Triculture plantings did not differ significantly from biculture plantings for any accumulation period. Survival Mean survival varied from 18 to 90% between the two grass species. Survival of P. amarum ranged form 75% to 100% for all spacing and planting combinations (Table 5). Differences among treatments were not detectable for P. amarum as all survival fell above 75%. Survival of S. maritimum ranged from 8 to 29% for all density and planting combinations. Survival was significantly higher (P = 0.0245) at 44 cm spacing where maximum plant foliage burial was 35% compared to 43% burial at 30 cm spacing. Planting combination did not have a significant effect on S. maritimum survival (P = 0.6607). Survival of I. imbricata ranged from 54% to 92% for all spacing and planting combinations. Survival did not differ significantly for 44 cm compared to 30 cm spacing (P = 0.0879). Planting combination significantly affected survival (P = 0.0029). Survival of I. imbricata was lower (P = 0.0313) when planted in combination with P. amarum (Table 5). Discussion Higher density plantings accumulated more sand during winter months. However, the effect of plant density and plant species on sand accumulation changed during spring months. The decreased relative difference in percent ground coverage by aboveground plant parts among species and planting combination with active spring growth and low survival of S. maritimum may cause this change. Initially, the wider spaced plantings

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50 (lower plant density) corresponded to lower percent foliar and basal coverage. As a result, wider spaced plantings presented less resistance to sand movement and thus, lower accumulation occurred. As plants began to grow bare areas between plants were reduced resulting in relatively less difference in exposed area between plantings spaced differently and therefore, the ability of sand to move in and out freely was similar between plantings. Although differences in percent cover can be initially assumed due to difference in plant density and uniformity of transplants, growth data would have quantified the change in percent cover. However, growth data was not collected before the loss of the experiment by overwash during tropical storm Arlene (June 11, 2005). The negative accumulation rate of monoculture plantings of S. maritimum during spring months (March May) appeared to result from high plant mortality. After plant death, the subsequent deconstruction of the dead foliage during the months of March -May released the previously trapped sand. Lower accumulation rates for plantings of P. amarum in combination with other species may be a result of the replacement of P. amarum plants with I. imbricata, which was less effective than P. amarum at trapping sand. Death of a high percentage of S. maritimum also resulted in lower sand accumulation when planted with P. amarum. In this study, I found no evidence of facilitation among P. amarum, I. imbricata and S. maritimum when planted in combination and at densities generally used in dune restoration. These results contradict those of (Franks and Peterson 2003) who suggested facilitation at higher densities positively effects plant survival and plant biomass in buried plots. Franks and Peterson also found that species richness had no effect on survival or biomass when plants were buried. However, there were differences between the two

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51 studies. Both density levels of my study fell between the high (50 cm) and low (20 cm) density levels of the Franks and Peterson study. In addition to I. imbricata, which was included in both studies, Franks and Peterson included different grasses, herbs, shrubs and vines, which were planted during the active growing season (July) and burial was applied as a one-time event. Greater sand accumulation associated with increased planting density appears to have negatively impacted survival of S. maritimum. After 33 days, the crowns of S. maritimum transplants were as much as 12.7 cm below the soil surface and as much as 43% of the foliage was buried which may have exceeded the threshold level of burial (Martinez and Psuty 2004), subjecting the plants to stress and possibly causing death Similarly, Franks and Peterson (2003), found a 54% reduction in survival when several dune species were buried to approximately 50% of their height. S. maritimum as a secondary colonizing grass replaces U. paniculata behind foredune ridges (Johnson 1997). Because S. maritimum is often found on the leeward side of dunes where sand movement and salt deposition are reduced (Craig 1991), it may be less tolerant of sand burial although salt spray tolerance can also influence plant zonation (Oosting 1945). Two secondary colonizing grasses, Schizachyrium scoparium and Trachypogon plumosis have also been shown to be intolerant of high levels of sand burial and are restricted to areas where sand movement is decreased (Martinez et al. 2001). However, my findings contradict an earlier study that found artificial burial with sand of 50 or 100% of foliar tissue increased plant dry weight of Schizachyrium scoparium above that of unburied controls Martinez and Moreno-Casasola (1996). Results for S. scoparium were recorded when plants were artificially buried while plants

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52 were actively growing (summer) as opposed to the results of my study where planting and natural sand burial occurred while plants were dormant (winter). Changes in environmental factors such as soil moisture and soil temperature in response to burial are the most important factors effecting plant growth and survival (Martinez et al. 2001). Burial during winter months may have decreased soil temperature and increased soil moisture to the detriment of plant survival. Wind speeds, sand movement and accumulation are greatest during winter months on Santa Rosa Island and may represent the least advantageous time to plant S. maritimum (Miller et al. 2001). In this study, S. maritimum survival was < 29% when planted in January in an overwash site on Santa Rosa Island. Yet, earlier studies on this island found 100% survival 2 1/2 yrs after planting when S. maritimum was planted during summer months behind a developing dune ridge (Thetford et al. 2005) and 100% survival (June until uprooted by hurricane Ivan (16 September, 2004)) when planted between condominiums less than 40 m from mean high tide line with no other dune structure landward of the planting (unpublished data). Conditions during winter months may limit the ability of S. maritimum to persist in foredunes with high sand accumulation rates. Future experiments are needed to determine what environmental factor or factors are responsible for the reduced survival of S. maritimum when planted in a foredune location during winter months. Competition from P. amarum may be responsible for the lower survival rates of I. imbricata. Franks (2003a) found reduced biomass of I. imbricata when planted in combination with U. paniculata, however he found an increase in survival of I. imbricata

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53 suggesting the simultaneous occurrence of facilitation and competition. Further research is needed to determine the tolerance of I. imbricata to competition. P. amarum is reported to be less tolerant of burial than Uniola paniculata and Ammophila breviligulata, especially during establishment (Woodhouse 1982); however, we found high survival rates during winter months when sand accumulation is highest for Santa Rosa Island (Miller et al. 2001). Survival rates ranging from 75% to 82% have been recorded for spring plantings of P. amarum (Seneca et al. 1976, Miller et al. 2001), which are similar to the survival rates found in this study. P. amarum spreads faster at sites receiving moderate amounts of sand accumulation compared to sites receiving little sand accumulation (Seneca et al. 1976). Moderate amounts of burial by sand have been shown to result in higher plant density, percent cover, and biomass per plant below a certain threshold level of burial (Maun 1998). My results suggest P. amarum is below its burial threshold when planted alone or in combination with plants and at densities used in this experiment in frontal dunes of Santa Rosa Island. Greater tolerance of P. amarum and I. imbricata to sand burial compared to S. maritimum may result from differences in height and growth form among species. S. maritimums low, prostrate growth may reduce its ability to tolerate burial resulting in the low survival rates seen in this experiment. However, S. maritimums may also be less tolerant of salt spray and the increased wind speeds and sand movement during winter months may have increased salt exposure. The upright growth form of I. imbricata transplants may confer an ability to tolerate sand accumulation. This species tolerance to saltwater overwash, saltspray, and sandblasting may also contribute to its survival when transplanted on an overwash site (Woodhouse 1982).

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54 Conclusions Effects of intermixed composite plantings on survival of P. amarum, I. imbricata, and S. maritimum ranged from neutral to negative when compared to monoculture plantings. The effect of composite plantings on mean sand accumulation when compared to monoculture plantings was neutral or negative for all species when compared to monoculture plantings. Survival rates of I. imbricata were reduced when planted in combination with other species, possibly as a result of interspecific competition, especially when planted in combination with P. amarum. High plant density (30 cm spacing) compared to low plant density (44 cm spacing) increased sand accumulation. However, increased burial may have led to high mortality rates for S. maritimum. Threshold level of burial for individual species determines whether or not increasing the initial rate of sand accumulation with higher plant density will have a negative affect on transplant survival rates. The varying responses to burial suggest that some species have a higher threshold of burial and will be better suited to rapid dune formation and some species will have a lower threshold level of burial and should be planted in areas or orientations where they are less likely to accumulate sand as quickly. This will result in increased survival rates and increase the efficiency of restoration.

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55 *Reprinted with permission of the publisher Figure 25. Map of Florida with insert showing the location of Santa Rosa Island. Arrows indicate the location of the six study sites and Santa Rosa Sound.

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56 Table 4. Incremental and Total sand accumulation (cm) of height gained for 30 cm and 44 cm spacings of Iva imbricata, Panicum amarum, and Schizachyrium maritimum planted in different combinations of 12 plants including a control (no plants). Combinations consisting of two species have six plants of each species planted and combinations consisting of three species have four plants of each species planted. Iva = Iva imbricata, Pan = Panicum amarum, Sch = Schizachyrium maritimum. Analysis of variance for main effects and contrasts, significance at P < 0.05. Period of Accumulation (days) 0-33 33-117 0-117 Spacing (cm) Planting Combination 30 44 30 44 30 44 Control 3.43 -1.14 -1.45 -0.91 1.98 -2.06 Iva 6.78 0.76 2.21 4.42 8.99 5.18 Pan 8.23 2.82 4.80 5.41 13.03 8.23 Sch 7.85 3.66 -0.50 -1.37 3.35 2.29 Iva+Pan 3.43 1.98 4.65 3.28 8.08 5.26 Iva+Sch 1.68 1.98 1.52 0.23 3.20 2.21 Pan+Sch 4.34 3.66 2.67 1.75 7.01 5.41 Iva+Pan+Sch 3.96 3.05 3.35 2.13 7.32 5.18 Analysis of Variance df Main effects p-value p-value p-value Rep 3 0.3548 0.4559 0.0232 Spacing 1 0.0592 0.8109 0.0038 Planting Combination 7 0.0542 <.0001 <.0001 Spacing*Planting Combination 7 0.3040 0.4116 0.9291 Contrasts Control versus Iva 1 0.0975 0.0005 0.0002 Control versus Pan 1 0.0072 <.0001 <.0001 Control versus Sch 1 0.0049 0.1483 0.1072 Iva versus Iva+Pan, Iva+Sch 1 0.2689 0.3899 0.1179 Pan versus Pan+Iva, Pan+Sch 1 0.1134 0.0567 0.0078 Sch versus Sch+Iva, Sch+Pan 1 0.0588 0.0013 0.0002 Iva+Pan, Iva+Sch, Pan+Sch versus Iva+Pan+Sch 1 0.6048 0.6874 0.4616

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57 Table 5. Mean survival (percent) for 30 cm and 44 cm spacings of Iva imbricata, Panicum amarum, and Schizachyrium maritimum planted in different combinations of 12 plants. Combinations consisting of one species have 12 plants of the same species planted and combinations consisting of two species have six plants of each species planted. Combinations consisting of three species have four plants of each species planted. Iva = Iva imbricata, Pan = Panicum amarum, Sch = Schizachyrium maritimum. Survival% Iva Pan Sch Spacing (cm) Planting Combination 30 44 30 44 30 44 Iva 88 92 * * Pan * 96 92 * Sch * * 17 29 Iva+Pan 63 54 88 75 * Iva+Sch 58 92 * 8 29 Pan+Sch * 83 96 8 21 Iva+Pan+Sch 71 83 100 88 17 17 Analysis of Variance df p-value p-value p-value Main effects Rep 5 0.0909 <.0001 Spacing 1 0.0879 0.0245 Rep*Spacing 5 0.9619 0.3595 Planting Combination 3 0.0029 0.6607 Contrasts Iva versus Iva+Pan 1 0.0313 * Iva versus Iva+Sch 1 0.3844 *

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APPENDIX MEANS AND STANDARD ERRORS FOR IVA IMBRICATA PROPAGATION STUDY Table 6. Iva imbricata stock-plants mean height (cm) and standard deviation of by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertilizer rate (fert) = fertility rates in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting. Experiment 1 Experiment 2 harvest fert N Mean Std dev harvest fert N Mean Std dev 1 5.5 12 26.6 6.26 1 5.5 12 27.2 4.86 1 11 12 38.4 5.74 1 11 12 29.6 7.50 1 15 12 40.8 5.36 1 15 12 31.2 5.02 1 21 12 40.8 6.81 1 21 12 30.4 5.33 2 5.5 12 28.5 4.64 2 5.5 12 30.1 3.55 2 11 12 34.0 4.65 2 11 12 30.2 3.30 2 15 12 31.9 3.80 2 15 12 29.4 4.23 2 21 12 33.6 4.48 2 21 12 28.8 3.31 3 5.5 12 33.8 2.78 3 5.5 12 27.4 2.02 3 11 12 36.3 4.17 3 11 12 25.7 3.60 3 15 12 37.6 5.44 3 15 12 26.7 2.80 3 21 12 36.7 3.38 3 21 12 25.6 2.71 4 5.5 12 30.6 4.93 4 5.5 12 26.5 3.23 4 11 12 35.1 4.44 4 11 12 26.7 4.08 4 15 11 34.6 3.83 4 15 12 26.9 3.06 4 21 12 37.9 4.36 4 21 12 23.0 4.97 58

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59 Table 7. Iva imbricata stock-plants mean width (cm) and standard deviation of by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertilizer rate (fert) = fertility rates in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting. Experiment 1 Experiment 2 harvest fert N Mean Std dev harvest fert N Mean Std dev 1 5.5 12 11.0 2.79 1 5.5 12 10.6 1.88 1 11 12 20.0 3.53 1 11 12 13.7 3.46 1 15 12 22.5 3.10 1 15 12 13.2 2.80 1 21 12 24.8 4.39 1 21 12 13.5 1.79 2 5.5 12 13.5 2.60 2 5.5 12 13.9 3.12 2 11 12 21.3 2.41 2 11 12 20.1 2.42 2 15 12 22.7 1.98 2 15 12 17.8 5.14 2 21 12 24.7 2.53 2 21 12 20.3 2.55 3 5.5 12 14.2 2.19 3 5.5 12 13.8 3.91 3 11 12 22.5 2.28 3 11 12 21.4 3.95 3 15 12 23.6 2.25 3 15 12 19.0 3.92 3 21 12 26.3 3.32 3 21 12 21.4 3.06 4 5.5 12 16.5 2.37 4 5.5 12 14.3 3.68 4 11 12 24.9 3.57 4 11 12 24.1 4.54 4 15 11 26.6 2.74 4 15 12 19.8 5.47 4 21 12 29.4 3.52 4 21 12 22.9 4.27

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60 Table 8. Iva imbricata stock-plants mean index (cm 3 ) and standard deviation of by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertilizer rate (fert) = fertility rates in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting. Experiment 1 Experiment 2 harvest fert N Mean Std dev harvest fert N Mean Std dev 1 5.5 12 18.8 4.42 1 5.5 12 18.9 2.86 1 11 12 29.2 4.03 1 11 12 21.7 4.15 1 15 12 31.7 3.46 1 15 12 22.2 3.32 1 21 12 32.8 4.60 1 21 12 21.9 2.59 2 5.5 12 21.0 3.21 2 5.5 12 22.0 2.93 2 11 12 27.7 2.77 2 11 12 25.1 1.99 2 15 12 27.3 2.36 2 15 12 23.6 4.31 2 21 12 29.1 3.05 2 21 12 24.5 2.36 3 5.5 12 24.0 1.76 3 5.5 12 20.6 2.64 3 11 12 29.4 2.23 3 11 12 23.5 2.39 3 15 12 30.6 2.41 3 15 12 22.9 2.71 3 21 12 31.5 2.57 3 21 12 23.5 1.93 4 5.5 12 23.5 3.21 4 5.5 12 20.4 3.12 4 11 12 30.0 3.36 4 11 12 25.4 3.25 4 15 11 30.6 2.20 4 15 12 23.4 3.83 4 21 12 33.7 2.81 4 21 12 22.9 3.39

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61 Table 9. Iva imbricata stock-plants mean total fresh weight (g) and standard deviation of by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertilizer rate (fert) = fertility rates in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting. Experiment 1 Experiment 2 harvest fert N Mean Std dev harvest fert N Mean Std dev 1 5.5 12 8.0 4.45 1 5.5 12 3.2 2.05 1 11 12 24.5 8.26 1 11 12 4.7 2.56 1 15 12 40.2 7.82 1 15 12 6.4 3.00 1 21 12 45.1 15.45 1 21 12 7.9 2.31 2 5.5 12 5.3 1.67 2 5.5 12 7.4 1.68 2 11 12 17.9 5.38 2 11 12 10.9 2.93 2 15 12 21.4 4.07 2 15 11 12.2 3.17 2 21 12 28.9 7.05 2 21 12 11.9 3.50 3 5.5 12 7.7 1.47 3 5.5 12 5.1 3.04 3 11 12 16.0 2.11 3 11 10 8.4 3.07 3 15 12 20.8 2.47 3 15 12 7.3 3.16 3 21 12 26.6 4.02 3 21 12 9.9 4.82 4 5.5 12 9.2 2.80 4 5.5 11 6.3 3.34 4 11 12 21.5 4.67 4 11 11 13.0 4.98 4 15 11 28.1 4.22 4 15 11 14.3 7.63 4 21 12 34.9 5.18 4 21 12 14.9 8.44

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62 Table 10. Mean number and standard deviation of cuttings harvested from of Iva imbricata stock-plants by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting. Experiment 1 Experiment 2 harvest fert N Mean Std dev harvest fert N Mean Std dev 1 5.5 12 4.0 0.74 1 5.5 12 3.5 1.93 1 11 12 7.6 2.23 1 11 12 4.9 3.15 1 15 12 12.6 3.75 1 15 12 7.0 3.84 1 21 12 11.2 3.13 1 21 12 8.6 2.31 2 5.5 12 7.5 2.35 2 5.5 12 7.3 2.27 2 11 12 17.5 5.45 2 11 12 11.1 2.68 2 15 12 23.6 4.42 2 15 12 10.3 4.52 2 21 12 27.2 6.56 2 21 12 10.1 3.63 3 5.5 12 8.5 2.39 3 5.5 12 3.5 2.02 3 11 12 18.4 4.12 3 11 12 5.7 3.80 3 15 12 24.2 4.30 3 15 12 5.8 2.63 3 21 12 30.8 5.22 3 21 12 6.8 3.49 4 5.5 12 10.1 3.00 4 5.5 12 4.2 2.98 4 11 12 22.5 5.65 4 11 12 8.1 4.66 4 15 11 30.3 5.18 4 15 12 8.4 5.09 4 21 12 34.5 5.90 4 21 12 9.7 6.87

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63 Table 11. Mean cutting weight (g) and standard deviation of cuttings harvested from of Iva imbricata stock-plants by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 1-4 = 49, 79, 108, and 136 days after potting. Experiment 1 Experiment 2 harvest fert N Mean Std dev harvest fert N Mean Std dev 1 5.5 12 1.6 0.66 1 5.5 12 0.9 0.28 1 11 12 2.3 1.06 1 11 12 1.0 0.42 1 15 12 2.0 0.46 1 15 12 1.0 0.20 1 21 12 2.6 0.65 1 21 12 0.9 0.14 2 5.5 12 0.7 0.01 2 5.5 12 1.1 0.27 2 11 12 1.0 0.02 2 11 12 1.0 0.18 2 15 12 0.9 0.01 2 15 11 1.1 0.25 2 21 12 1.1 0.01 2 21 12 1.2 0.21 3 5.5 12 0.9 0.18 3 5.5 12 1.5 0.32 3 11 12 0.9 0.16 3 11 10 1.3 0.35 3 15 12 0.9 0.13 3 15 12 1.4 0.31 3 21 12 0.9 0.12 3 21 12 1.4 0.18 4 5.5 12 0.9 0.10 4 5.5 11 1.5 0.40 4 11 12 1.0 0.19 4 11 11 1.5 0.26 4 15 11 1.0 0.22 4 15 11 1.6 0.29 4 21 12 1.0 0.14 4 21 12 1.7 0.32

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64 Table 12. Mean root length (cm) and standard deviation of cuttings harvested from of Iva imbricata stock-plants by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 2-4 = 79, 108, and 136 days after potting. Experiment 1 Experiment 2 harvest fert N Mean Std dev harvest fert N Mean Std dev 1 5.5 46 6.2 3.01 * * 1 11 43 7.1 3.71 * * 1 15 42 5.1 2.81 * * 1 21 44 4.7 2.57 * * 2 5.5 38 3.4 1.55 2 5.5 48 9.6 3.15 2 11 38 3.6 1.94 2 11 48 11.4 3.24 2 15 34 2.9 1.87 2 15 44 12.2 3.16 2 21 26 3.3 2.61 2 21 46 12.3 3.23 3 5.5 30 3.3 1.66 3 5.5 35 5.0 2.20 3 11 25 3.9 2.38 3 11 38 4.9 2.86 3 15 25 3.5 2.33 3 15 42 5.0 2.34 3 21 17 3.9 2.12 3 21 45 5.4 2.33 4 5.5 48 4.9 2.93 4 5.5 31 2.3 1.33 4 11 44 5.6 2.74 4 11 36 1.9 1.70 4 15 48 5.8 2.96 4 15 31 1.7 1.33 4 21 48 6.3 3.31 4 21 40 2.0 1.97

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65 Table 13. Mean root numberand standard deviation of cuttings harvested from o f Iva imbricata stock-plants by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 2-4 = 79, 108, and 136 days after potting. Experiment 1 Experiment 2 harvest fert N Mean Std dev harvest fert N Mean Std dev 1 5.5 46 8.7 4.03 * * 1 11 43 9.7 4.55 * * 1 15 42 6.5 4.70 * * 1 21 44 6.4 4.09 * * 2 5.5 38 5.8 2.93 2 5.5 48 11.5 5.04 2 11 38 6.0 3.71 2 11 48 12.0 5.23 2 15 34 4.8 3.34 2 15 44 14.7 4.85 2 21 26 4.3 3.26 2 21 46 13.9 5.04 3 5.5 29 4.6 2.80 3 5.5 35 9.1 3.85 3 11 25 4.7 3.06 3 11 38 6.2 3.40 3 15 25 4.2 4.36 3 15 42 8.9 3.90 3 21 17 4.1 3.93 3 21 45 8.0 3.13 4 5.5 48 6.0 3.36 4 5.5 35 6.9 4.20 4 11 44 6.2 2.90 4 11 44 5.1 3.77 4 15 48 6.4 2.86 4 15 42 5.5 4.78 4 21 48 6.9 3.48 4 21 46 5.9 4.01

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66 Table 14. Mean root index (cm) and standard deviation of cuttings harvested from of Iva imbricata stock-plants by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 2-4 = 79, 108, and 136 days after potting. Experiment 1 Experiment 2 harvest fert N Mean Std dev harvest fert N Mean Std dev 1 5.5 46 57.5 41.0 * * 1 11 43 77.3 62.1 * * 1 15 42 37.8 37.0 * * 1 21 44 36.3 36.4 * * 2 5.5 38 22.3 15.3 2 5.5 48 111.4 58.9 2 11 38 27.0 24.3 2 11 48 136.3 66.4 2 15 34 17.5 18.3 2 15 44 179.2 68.2 2 21 26 21.0 33.8 2 21 46 174.3 85.5 3 5.5 29 16.9 15.3 3 5.5 35 47.7 27.1 3 11 25 22.5 19.9 3 11 38 35.3 27.2 3 15 25 21.9 31.1 3 15 42 48.4 36.1 3 21 17 20.2 26.8 3 21 45 47.0 27.4 4 5.5 48 35.5 34.7 4 5.5 31 19.6 14.3 4 11 44 37.9 26.7 4 11 36 13.4 15.3 4 15 48 41.2 29.9 4 15 31 14.0 14.9 4 21 48 49.1 35.0 4 21 40 14.7 16.6

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67 Table 15. Mean rooting percentage and standard deviation of cuttings harvested from of Iva imbricata stock-plants by harvest and fertility rate using repeated measures of proc mixed (SAS Institute Inc. 2000-2004). Fertility rate (fert) in (g) Osmocote/1 gallon container. Experiment 1, harvests 1-4 = 114, 146, 175, and 206 days after potting. Experiment 2, harvests 2-4 = 79, 108, and 136 days after potting. Experiment 1 Experiment 2 harvest fert N Mean % Std dev harvest fert N Mean % Std dev 1 5.5 48 95.8 20.19 * * 1 11 48 89.6 30.87 * * 1 15 48 87.5 33.42 * * 1 21 48 91.7 27.93 * * 2 5.5 48 79.2 41.04 2 5.5 48 100.0 0.00 2 11 48 79.2 41.04 2 11 48 100.0 0.00 2 15 48 70.8 45.93 2 15 48 91.7 27.93 2 21 48 54.2 50.35 2 21 48 95.8 20.19 3 5.5 48 62.5 48.92 3 5.5 48 72.9 44.91 3 11 48 52.1 50.49 3 11 46 78.3 41.70 3 15 48 52.1 50.49 3 15 48 87.5 33.42 3 21 48 35.4 48.33 3 21 47 93.6 24.71 4 5.5 46 100.0 0.00 4 5.5 48 64.6 48.33 4 11 47 91.5 28.21 4 11 48 75.0 43.76 4 15 47 100.0 0.00 4 15 48 64.6 48.33 4 21 47 100.0 0.00 4 21 48 83.3 37.66

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LIST OF REFERENCES Bertness, M. D. 1991. Interspecific Interactions among High Marsh Perennials in a New-England Salt-Marsh. Ecology 72:125-137. Bertness, M. D., and R. Callaway. 1994. Positive Interactions in Communities. Trends in Ecology & Evolution 9:191-193. Bertness, M. D., and S. D. Hacker. 1994. Physical Stress and Positive Associations among Marsh Plants. American Naturalist 144:363-372. Blazich, F. A. 1988. Mineral Nutrition and Adventitious Rooting. Pages 61-69 in N. Sankhla, editor. Adventitious root formation in cuttings. Dioscorides Press, Portland, OR. Bruno, J. F., J. J. Stachowicz, and M. D. Bertness. 2003. Inclusion of facilitation into ecological theory. Trends in Ecology & Evolution 18:119-125. Callaway, R. M. 1995. Positive interactions among plants. Botanical Review 61:306-349. Callaway, R. M., and L. R. Walker. 1997. Competition and facilitation: A synthetic approach to interactions in plant communities. Ecology 78:1958-1965. Cameron, R. W. F., R. S. Harrison-Murray, H. L. Judd, T. R. Marks, Y. Y. Ford, and C. H. A. Bates. 2005. The effects of photoperiod and light spectrum on stock-plant growth and rooting of cuttings of Cotinus coggygria 'Royal Purple'. Journal of Horticultural Science & Biotechnology 80:245-253. Clements, F. E., J. Weaver, and H. Hanson. 1916. Plant Competition: An Analysis of the Development of Vegetation. Pages 512 in Carnagie Institute, New York, Washington D.C. Clewell, A. F. 1986. Natural Setting and Vegetation of the Florida Panhandle. COESAM/PDEI-86/001, reissued by the author, 1997, U.S. Army Corps of Engineers, Mobile District. Colosi, J. C., and J. F. McCormick. 1978. Population-Structure of Iva-Imbricata in 5 Coastal Dune Habitats. Bulletin of the Torrey Botanical Club 105:175-186. Connell, J. H., and R. O. Slatyer. 1977. Mechanisms of Succession in Natural Communities and Their Role in Community Stability and Organization. American Naturalist 111:1119-1144. 68

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69 Craig, R. M. 1991. Plants for coastal dunes of the Gulf and south Atlantic coasts and Puerto Rico. U.S. Dept. of Agriculture, Soil Conservation Service. Dahl, B. E., B. A. Fall, A. Lohse, and S. G. Appan. 1975. Construction and stabilization of coastal foredunes with vegetation:Padre Island, Texas. in U.S. Army corps of Engineers, Coastal Engineering Research Center, Fort Belvoir, Virginia. Dahl, B. E., J. P. Goen, Coastal Engineering Research Center (U.S.)., and Texas Tech University. Dept. of Range and Wildlife Management. 1977. Monitoring of foredunes on Padre Island, Texas. Dept. of Defense for sale by the National Technical Information Service, Fort Belvoir, Va. Springfield, Va. De Villiers, A. J., M. W. Van Rooyen, and G. K. Theron. 2001. The role of facilitation in seedling recruitment and survival patterns, in the Strandveld Succulent Karoo, South Africa. Journal of Arid Environments 49:809-821. Ehrenfeld, J. G. 1990. Dynamics and Processes of Barrier-Island Vegetation. Reviews in Aquatic Sciences 2:437-480. Faust, J. E., and L. W. Grimes. 2005. Pinch height of stock-plants during scaffold development affects cutting production. Hortscience 40:650-653. Franks, S. J. 2003a. Competitive and facilitative interactions within and between two species of coastal dune perennials. Canadian Journal of Botany-Revue Canadienne De Botanique 81:330-337. Franks, S. J. 2003b. Facilitation in multiple life-history stages: evidence for nucleated succession in coastal dunes. Plant Ecology 168:1-11. Franks, S. J., and C. J. Peterson. 2003. Burial disturbance leads to facilitation among coastal dune plants. Plant Ecology 168:13-21. Gagne, J. M., and G. Houle. 2001. Facilitation of Leymus mollis by Honckenya peploides on coastal dunes in subarctic Quebec, Canada. Canadian Journal of Botany-Revue Canadienne De Botanique 79:1327-1331. Ganmore-Neuman, R., and A. Hagiladi. 1990. Effect of the NO3-/NH4+ ratio in nutrient solution on Pelargonium stock-plants. Yield and quality of cuttings. Journal of Plant Nutrition:1241-1256. Ganmore-Neuman, R., and A. Hagiladi. 1992. Plant growth and cutting production of container grown Pelargonium stock-plants as affected by N concentration and N form. Journal of the American Society for Horticultural Science:234-238. Gibson, J. L. 2003. Influence of mineral nutrition on stock-plant yield and subsequent rooting of stem cuttings of Scaevola, New Guinea impatiens, and vegetative strawflower. Dissertation. Nort Carolina State University, Raleigh.

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70 Goldberg, D. E., T. Rajaniemi, J. Gurevitch, and A. Stewart-Oaten. 1999. Empirical approaches to quantifying interaction intensity: Competition and facilitation along productivity gradients. Ecology 80:1118-1131. Gore, J. A., and T. L. Schaefer. 1993. Santa Rosa Beach Mouse Survey. Florida Game and Fresh Water Fish Commission, Tallahassee, FL. Haun, J. R., and P. W. Cornell. 1951. Rooting Response of Geranium (Pelargonium hortorum, Bailey var. Richard) cuttings as Influenced by Nitrogen, Phosphorus, and Potassium Nutrition on the Stock-plant. Proceedings of the American Society of Horticultural Science 58:317-323. Henry, P. H., F. A. Blazich, and L. E. Hinesley. 1992. Nitrogen Nutrition of Containerized Eastern Redcedar .2. Influence of Stock-plant Fertility on Adventitious Rooting of Stem Cuttings. Journal of the American Society for Horticultural Science 117:568-570. Hunter, A. F., and L. W. Aarssen. 1988. Plants Helping Plants. Bioscience 38:34-40. Johnson, A. F. 1997. Rates of vegetation succession on a coastal dune system in northwest Florida. Journal of Coastal Research 13:373-384. Kellman, M., and M. Kading. 1992. Facilitation of Tree Seedling Establishment in a Sand Dune Succession. Journal of Vegetation Science 3:679-688. Li, X. D., and S. D. Wilson. 1998. Facilitation among woody plants establishing in an old field. Ecology 79:2694-2705. Maestre, F. T., and J. Cortina. 2004. Do positive interactions increase with abiotic stress? A test from a semi-arid steppe. Proceedings of the Royal Society of London Series B-Biological Sciences 271:S331-S333. Martinez, M. L. 2003. Facilitation of seedling establishment by an endemic shrub in tropical coastal sand dunes. Plant Ecology 168:333-345. Martinez, M. L., and P. Moreno-Casasola. 1996. Effects of burial by sand on seedling growth and survival in six tropical sand dune species from the Gulf of Mexico. Journal of Coastal Research 12:406-419. Martinez, M. L., and N. P. Psuty. 2004. Coastal Dunes: Ecology and Conservation. Springer, Berlin, New York. Martinez, M. L., G. Vazquez, and S. Sanchez Colon. 2001. Spatial and temporal variability during primary succession on tropical coastal sand dunes. Journal of Vegetation Science 12:361-372. Maun, M. A. 1998. Adaptations of plants to burial in coastal sand dunes. Canadian Journal of Botany-Revue Canadienne De Botanique 76:713-738.

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71 Maun, M. A., and P. R. Baye. 1989. The Ecology of Ammophilia breviligulata Fern. on Coastal Dune Systems. CRC Critical Review Aquatic Sciences:661-681. Miller, D. L., M. Thetford, and L. Yager. 2001. Evaluation of sand fence and vegetation for dune building following overwash by hurricane Opal on Santa Rosa Island, Florida. Journal of Coastal Research 17:936-948. Morton, R. A., T. Miller, and L. Moore. 2005. Historical shoreline changes along the US Gulf of Mexico: A summary of recent shoreline comparisons and analyses. Journal of Coastal Research 21:704-709. Moyers, J. E. 1996. Food habits of Gulf Coast subspecies of beach mice (Peromyscus polionotus spp): M.S. thesis. Auburn University, Auburn, AL. Niering, W. A., C. H. Lowe, R. Whittaker, and R. H. Whittaker. 1963. Saguaro a Population in Relation to Environment. Science 142:15-&. Oosting, H. J. 1945. Tolerance to Salt Spray of Plants of Coastal Dunes. Ecology 26:85-89. Otvos, E. G. 1982. Santa Rosa Island, Florida Panhandle, Origins of a composite barrier island. Southern Geology 23:15-28. Otvos, E. G. 2005. Coastal barriers, Gulf of Mexico: Holocene evolution and chronology. Journal of Coastal Research:141-163. Preston, W. H., Jr., J. B. Shanks, and P. W. Cornell. 1953. Influence of Mineral Nutrition on Production, Rooting and Survival of Cuttings of Azaleas. Proceedings of the American Society of Horticultural Science 61:499-507. Pugnaire, F. I., P. Haase, J. Puigdefabregas, M. Cueto, S. C. Clark, and L. D. Incoll. 1996. Facilitation and succession under the canopy of a leguminous shrub, Retama sphaerocarpa, in a semi-arid environment in south-east Spain. Oikos 76:455-464. Rudgers, J. A., and J. L. Maron. 2003. Facilitation between coastal dune shrubs: a non-nitrogen fixing shrub facilitates establishment of a nitrogen-fixer. Oikos 102:75-84. Statistical Analysis Software Institute Inc. 2000-2004. Help and Documentation. in. Statistical Analysis Software Institute Inc., Cary, NC. Seneca, E. D., W. W. Woodhouse, S. W. Broome, and Coastal Engineering Research Center (U.S.). 1976. Dune stabilization with Panicum Amarum along the North Carolina coast. U.S. for sale by the National Technical Information Service, Fort Belvoir, Va. Springfield, Va. Snyder, R. A., and C. L. Boss. 2002. Recovery and stability in barrier island plant communities. Journal of Coastal Research 18:530-536.

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72 Swilling, W. R., M. C. Wooten, N. R. Holler, and W. J. Lynn. 1998. Population dynamics of Alabama beach mice (Peromyscus polionotus ammobates) following Hurricane Opal. American Midland Naturalist 140:287-298. Thetford, M., and D. L. Miller. 2002. Propagation of 4 Florida Coastal Dune Species. Native Plants Journal Vol.3(2):112-120. Thetford, M., and D. L. Miller 2004a. Propagation and Production of Gulf Bluestem. EDIS document ENH974, University of Florida, Institute of Food and Agricultural Sciences. Thetford, M., and D. L. Miller 2004b. Propagation and Production of Seacoast Marshelder. EDIS document ENH975, University of Florida, Institute of Food and Agricultural Sciences. Thetford, M., D. L. Miller K. Smith, and M. Schneider. 2005. Container Size and Planting Zone Influence on Transplant Survival and Growth of Two Coastal Plants. Hort Technology July-September 15(3). Veierskov, B. 1988. Relations Between Carbohydrates and Adventitious Root Formation. Pages 70-78 in N. Sankhla, editor. Adventitious root formation in cuttings. Dioscorides Press, Portland, OR. Webb, C. A., D. M. Bush, and R. S. Young. 1997. Property damage mitigation lessons from Hurricane Opal: The Florida panhandle coast, October 4, 1995. Journal of Coastal Research 13:246-252. Woodhouse, W. W. 1978. Dune Building and Stabilization with Vegetation:Special Report No. 3. U.S. Army Corps of Engineers, Coastal Engineering Research Center, Fort Belvoir, Virginia. Woodhouse, W. W. 1982. Creation and Restoration of Coastal Plant Communities. CRC Press, Inc., Boca Raton, FL. Woodhouse, W. W., E. D. Seneca, and C. A.W. 1968. Use of Sea Oats for Dune Stabilization in the Southeast. Shore Beach:15-21. Yuan, T., M. A. Maun, and W. G. Hopkins. 1993. Effects of Sand Accretion on Photosynthesis, Leaf-Water Potential and Morphology of 2 Dune Grasses. Functional Ecology 7:676-682.

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BIOGRAPHICAL SKETCH Josiah graduated from Pensacola High School in 1992. He took many college prep courses during high school but did not begin college until 1997. Josiah worked various jobs that ranged from cooking in a seafood restaurant to working as an automobile mechanic. The skills that he learned during that time are still valuable lessons in his life today. He began his college career by attending Pensacola Junior College from January 1997 to December 1999. After graduating with honors with an A.A. degree in environmental horticulture, he was accepted by the University of Florida to continue his college education. He began classes in the University of Floridas Environmental Horticulture program located at the West Florida Research and Educational Center in Milton, Florida, where he attended classes from January 2001 to May 2002. Josiah graduated as a University Scholar with highest honors. While at the West Florida Research and Educational Center he completed an undergraduate research project observing the genetic diversity of Red Baron Cogongrass. He presented his research at the southern Nurseryman Association conference and was awarded first place in the undergraduate research competition. Josiah worked as a Sr. Laboratory Technician under Dr. Mack Thetford during the final semester of his undergraduate degree. He continued to manage his lab group until December 2003 when he left to attend Graduate School at the University of Florida in Gainesville. Josiah entered the masters program in interdisciplinary ecology in the School of Natural Resources and Conservation. In Gainesville, he began to study coastal restoration, specifically looking at plant 73

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74 interactions during dune restoration. Hurricanes and tropical storms repeatedly destroyed his research, but he was able to gather enough information to complete his thesis. Josiah currently works with the Department of Environmental Protection in Pensacola, Florida. He does not see himself continuing his education in a university setting. When asked to look back at his college career, Josiah states that there are two important factors that stand out in his mind. First, the time he took off between high school and college taught him many things that helped him become better student. The second is financial aid, without which, he would not have been able to afford to go to college.