Evaluating the Effectiveness of Wetland
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EVALUATING THE EFFECTIVENESS OF WETLAND ASSESSMENT METHODS FOR DETERMINING THE CONDITION OF DEPRESSIONAL AND LACUSTRINE FRINGE WETLANDS IN OKLAHOMA By SARAH GALLAWAY Bachelor of Science in Natural Resource Management Texas Tech University Lubbock, Texas 2013 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE July, 2017 EVALUATING THE EFFECTIVENESS OF WETLAND ASSESSMENT METHODS FOR DETERMINING THE CONDITION OF DEPRESSIONAL AND LACUSTRINE FRINGE WETLANDS IN OKLAHOMA Thesis Approved: Craig Davis Thesis Adviser Sam Fuhlendorf Andy Dzialowski ii ACKNOWLEDGEMENTS First and foremost, I would like to thank my adviser, Dr. Craig Davis, for providing me with an opportunity to pursue a graduate degree and offering support, insight, and guidance throughout the process. This research was funded through a U.S. Environmental Protection Agency Wetland Program Development Grant. I would also like to thank my committee members, Sam Fuhlendorf and Andy Dzialowski. I also greatly appreciate the hardwork and dedication of Anthony Thornton, along with the other technicians who helped to make this project possible. Additionally, I would like to give a special thanks to Dan Dvorett for his continued support and friendship over the past three years, as well as to Brooks Tramell for providing me with an opportunity to continue working in wetland conservation. Lastly, I would like to thank my family for their support throughout the years, especially Ryon for his patience, words of encouragement, and unwavering confidence in me. iii Acknowledgements reflect the views of the author and are not endorsed by committee members or Oklahoma State University. Name: SARAH GALLAWAY Date of Degree: JULY, 2017 Title of Study: EVALUATING THE EFFECTIVENESS OF WETLAND ASSESSMENT METHODS FOR DETERMINING THE CONDITION OF DEPRESSIONAL AND LACUSTRINE FRINGE WETLANDS IN OKLAHOMA Major Field: NATURAL RESOURCE ECOLOGY AND MANAGEMENT Abstract: The U.S. Environmental Protection Agency has developed a three-tiered framework to categorize wetland assessments. Level 1 assessments are conducted remotely and condition is evaluated based on surrounding land-use. Level 2 assessments rely on rapid assessment methods (RAMs) to evaluate condition. Level 3 assessments use the most intensive sampling techniques to produce quantitative data. RAMs have become the preferred method for many programs, because they are conducted on-site, and require less time and expertise than Level 3 methods. Because RAMs are based on best professional judgment and inferred relationships between indicators of stress and wetland condition, validation with intensive data is necessary to confirm that condition scores are reflected in quantifiable components of the ecosystem. Chapter 1 presents our validation analysis of the Oklahoma Rapid Assessment Method (OKRAM) in 28 depressional wetlands across the state. We found strong, consistent relationships between OKRAM scores and Level 1 (e.g., Landscape Development Intensity Index) and Level 3 (e.g., plant and soil) data to suggest that OKRAM is tracking condition within the wetland as well as with anthropogenic disturbance factors in the surrounding landscape. Chapter 2 presents the initial application of OKRAM in 30 lacustrine fringe wetlands within central Oklahoma, alongside abiotic (e.g., soil and water quality) and biotic (e.g., vegetation and macroinvertebrate) data collection. Our analysis did not reveal consistent relationships between OKRAM and intensive data, indicating the method requires further modification. In addition to RAMs, Floristic Quality Assessment (FQA) is also used to evaluate wetland condition and guide conservation and management efforts. FQA results are assumed to be valid across large regions, despite areas of high environmental variability. Given the diverse ecoregions and environmental gradients across the state, Oklahoma provides an opportunity to examine spatial variation on FQA results. Chapter 3 presents our evaluation of 68 depressional wetlands to examine the influence of environmental variation on FQI scores. We found substantial variation between reference wetlands based on location, with higher scores occurring in the east (high precipitation) and lower scores occurring in the west (low precipitation). Our results highlight the importance of considering regional environmental differences when developing thresholds for wetland assessments. iv TABLE OF CONTENTS Chapter Page I. VALIDATION OF THE OKLAHOMA RAPID ASSESSMENT METHOD (OKRAM) IN DEPRESSIONAL WETLANDS USING EPA’S THREE-TIERED FRAMEWORK........................................................................................................1 Introduction ..............................................................................................................2 Methods....................................................................................................................7 Results ....................................................................................................................13 Discussion ..............................................................................................................15 Conclusion .............................................................................................................22 Literature Cited ......................................................................................................24 Figures and Tables .................................................................................................29 II. DEVELOPMENT OF A RAPID ASSESSMENT METHOD FOR DETERMINING THE CONDITION OF LACUSTRINE FRINGE WETLANDS IN CENTRAL OKLAHOMA ........................................................................................................37 Introduction ............................................................................................................38 Methods..................................................................................................................43 Results ....................................................................................................................51 Discussion ..............................................................................................................53 Conclusion .............................................................................................................63 Literature Cited ......................................................................................................64 Figures and Tables .................................................................................................71 III. EVALUATING THE EFFECTIVENESS OF FLORISTIC QUALITY ASSESSMENT AS A TOOL FOR DETERMINING THE CONDITION OF DEPRESSIONAL WETLANDS IN OKLAHOMA .............................................79 Introduction ............................................................................................................80 Methods..................................................................................................................85 Results ....................................................................................................................92 Discussion ..............................................................................................................95 Conclusion ...........................................................................................................103 Literature Cited ....................................................................................................104 Figures and Tables ...............................................................................................113 v APPENDICES ...........................................................................................................120 vi LIST OF TABLES Table Page Chapter 1 1. Descriptions of depressional wetlands sampled in 2015 across Oklahoma .....32 2. Land-use classes and coefficients for calculating Landscape Development Intensity Index scores ......................................................................................32 3. Relationships of Landscape Development Intensity Index scores with OKRAM scores and Level 3 data ....................................................................................33 4. Relationships of OKRAM attributes and overall scores with vegetation and soil chemistry data ..................................................................................................34 5. Repeatability analysis and evaluation of seasonal influences on OKRAM metrics and attributes ....................................................................................................35 6. Comparison of a priori classifications with condition classes assigned based on OKRAM scores. ..............................................................................................36 Chapter 2 1. Descriptions of lacustrine fringe wetlands sampled in 2014 within central Oklahoma .........................................................................................................75 2. Land-use classes and coefficients for calculating Landscape Development Intensity Index scores ......................................................................................75 3. Relationships of OKRAM attributes and overall scores with Level 3 data .....76 4. Relationships between Landscape Development Intensity Index scores and OKRAM, CRAM, and FACWet scores ...........................................................77