EVALUATING THE LOCATION, EXTENT, AND CONDITION OF ISOLATED WETLANDS IN THE DOUGHERTY PLAIN, GEORGIA, USA by GLENN I. MARTIN (Under the Direction of Jeffrey Hepinstall-Cymerman) ABSTRACT Geographically isolated wetlands are common throughout Georgia’s Dougherty Plain physiographic district, and provide many valuable ecosystem services. However, they are currently excluded from federal and state protection. To better understand the isolated wetland resource, we created a spatially-explicit timeline of land use and land cover within Dougherty Plain, developed a spatial map of isolated wetlands, and constructed a multi-metric framework to assess the ecological condition of 40 isolated wetlands at multiple scales. We found drastic shifts in land use and land cover between 1948 and 2007. We estimate that there are approximately 11,620 isolated wetlands covering 42,431 ha within the Dougherty Plain. The ecological assessment showed strong correlation between assessment methods and scales, and indicates that a remote assessment may be suitable for future studies. Future research can use this information to identify isolated wetlands in the Dougherty Plain, explore their land cover trajectories, and assess their ecological condition. INDEX WORDS: Dougherty Plain, Georgia, ecological assessment, isolated wetland, land cover, land use, EVALUATING THE LOCATION, EXTENT, AND CONDITION OF ISOLATED WETLANDS IN THE DOUGHERTY PLAIN, GEORGIA, USA by GLENN I. MARTIN B.S., The University of Georgia, 2005 A Thesis Submitted to the Graduate Faculty of The University of Georgia in Partial Fulfillment of the Requirements for the Degree MASTER OF SCIENCE ATHENS, GEORGIA 2010 © 2010 GLENN I. MARTIN All Rights Reserved EVALUATING THE LOCATION, EXTENT, AND CONDITION OF ISOLATED WETLANDS IN THE DOUGHERTY PLAIN, GEORGIA, USA by GLENN I. MARTIN Major Professor: Jeffrey Hepinstall-Cymerman Committee: L. Katherine Kirkman Stephen W. Golladay Electronic Version Approved: Maureen Grasso Dean of the Graduate School The University of Georgia December 2010 iv ACKNOWLEDGEMENTS I am deeply grateful to “The Boss” for making this research possible. I thank my advisor and committee for their advice, support, and encouragement. I also recognize the contributions and assistance of Dr. Mike Connor, Larry Etheridge, Liz Cox, Jean Brock, and the Plant Ecology and Aquatic Ecology labs at Ichauway. I am grateful to the many private landowners who supported this research by granting access to their land. Thanks to my family for instilling in me a love of nature. I am indebted to my wife, Hayden, for her sacrifice and support during this process; it did not go unnoticed. This project was supported by the Joseph W. Jones Ecological Research Center, the Robert W. Woodruff Foundation, and the University of Georgia. v TABLE OF CONTENTS Page ACKNOWLEDGEMENTS ........................................................................................................... iv LIST OF TABLES ........................................................................................................................ vii LIST OF FIGURES .........................................................................................................................x CHAPTER 1 INTRODUCTION .........................................................................................................1 PROJECT OVERVIEW ............................................................................................1 LITERATURE REVIEW ..........................................................................................2 OBJECTIVES .........................................................................................................24 LITEATURE CITED ..............................................................................................25 2 SIX DECADES (1948 – 2007) OF LANDSCAPE CHANGE IN THE DOUGHERTY PLAIN OF SOUTHWEST GEORGIA, USA .........................................................40 ABSTRACT ............................................................................................................41 INTRODUCTION ...................................................................................................42 METHODS ..............................................................................................................43 RESULTS ................................................................................................................47 DISCUSSION .........................................................................................................50 CONCLUSIONS .....................................................................................................54 ACKNOWLEDGEMENTS ....................................................................................55 LITERATURE CITED ............................................................................................55 APPENDIX A .........................................................................................................70 vi 3 MAPPING GEOGRAPHICALLY ISOLATED WETLANDS IN THE DOUGHERTY PLAIN, GEORGIA, USA .............................................................78 ABSTRACT ............................................................................................................79 INTRODUCTION ...................................................................................................80 METHODS ..............................................................................................................84 RESULTS ................................................................................................................90 DISCUSSION .........................................................................................................92 ACKNOWLEDGEMENTS ....................................................................................95 LITERATURE CITED ............................................................................................95 4 DEVELOPING A WETLAND ASSESSMENT FRAMEWORK FOR ISOLATED WETLANDS IN THE DOUGHERTY PLAIN, GEORGIA, USA ......................109 ABSTRACT ..........................................................................................................110 INTRODUCTION .................................................................................................111 METHODS ............................................................................................................113 RESULTS ..............................................................................................................119 DISCUSSION .......................................................................................................120 ACKNOWLEDGEMENTS ..................................................................................123 LITERATURE CITED ..........................................................................................123 APPENDIX A .......................................................................................................134 5 SUMMARY ...............................................................................................................153 LITERATURE CITED ..........................................................................................157 vii LIST OF TABLES Page Table 2.1: Name and description of land use and land cover classes ............................................60 Table 2.2: Description of land use and land cover metrics ............................................................61 Table 2.3: Median values of land use and land cover pattern metrics for the total sample landscape (Landscape) and individual LULC classes in the Dougherty Plain, Georgia, USA ...............................................................................................................................63 Table 2.4: Estimate of mean area (km2) and 95% confidence intervals around these means for each land use and land cover class throughout the entire Dougherty Plain in each sample year ....................................................................................................................64 Table 3.1: Accuracy and wetland statistics of GIS-based model results of isolated wetlands in the Dougherty Plain, Georgia, USA. ...................................................................................99 Table 4.1: Land cover classification scheme ...............................................................................126 Table 4.2: Correlations of metrics from assessment Levels 2 and 3 with LDI index values calculated from 2009 aerial photographs ....................................................................127 Table 4.3: Testing the ability of individual Level 2 and Level 3 metrics to differentiate between “low” (LDI < 2.00) (n = 20) and “high” (LDI ≥ 2.00) (n = 20) wetland groups using Mann-Whitney U Tests ...............................................................................................129 Table 4.4: Spearman’s rank correlations of Wetland Condition Indices (WCIs) with LDI index values calculated from 2009 aerial photographs, 2005 Georgia Land Use Trends (GLUT) data, 2001 National Land Cover Data (NLCD), 1998 18-class Georgia land cover data (GA18), and 1998 44-class Georgia land cover data (GA44) ...................130 viii Table A.1: Field delineated areas (hectare) of the 40 sample wetlands.......................................135 Table A.2: Level 1 – Remote Assessment scores for each sample wetland ................................137 Table A.3: Level 2 – Rapid Assessment scores for