The Impact of Woody Debris on Bank Stability and Macroinvertebrates in Intermittent

The Impact of Woody Debris on Bank Stability and Macroinvertebrates in Intermittent Headwater Streams within the Western Allegheny Plateau A thesis presented to the faculty of the Voinovich School of Leadership and Public Affairs of Ohio University In partial fulfillment of the requirements for the degree Master of Science Gabrielle N. Russell May 2018© 2018 Gabrielle N. Russell. All Rights Reserved. 2 This thesis titled The Impact of Woody Debris on Bank Stability and Macroinvertebrates in Intermittent Headwater Streams within the Western Allegheny Plateau by GABRIELLE N. RUSSELL has been approved for the Program of Environmental Studies and the Voinovich School of Leadership and Public Affairs by Kelly Johnson Associate Professor of Biological Sciences Mark Weinberg Dean, Voinovich School of Leadership and Public Affairs 3 ABSTRACT RUSSELL, GABRIELLE N., M.S., May 2018, Environmental Studies The Impact of Woody Debris on Bank Stability and Macroinvertebrates in Intermittent Headwater Streams within the Western Allegheny Plateau Director of Thesis: Kelly Johnson The primary purpose of this thesis research is to explore relationships between large woody debris (LWD), biological integrity, and bank stability within intermittent headwater streams in the Alleghany Plateau ecoregion. Ten streams were selected from throughout the ecoregion to determine correlations between the amounts of naturally occurring LWD, defined as any piece of woody with a diameter greater than 0.1 m and 0.5 m in length, macroinvertebrate diversity and abundance, stream power, substrate characteristics (pebble counts) and relative bank stability using a modified bank erosion index. We hypothesized that streams with higher quantities of naturally occurring woody debris will have hydraulic alteration that increases bank stability, and provide better habitat for macroinvertebrates. Specifically, we hypothesized woody debris volume will be positively correlated with Headwater Macroinvertebrate Field Evaluation Index, percent EPT, # of individuals, taxa richness, median particle size and modified Bank Erosion Hazard Index. Other stream characteristics were calculated to understand overall stream function, such as gradient, flow, stream power, unit stream power, and land use. To test this hypothesis a correlation matrix was created to determine any significant relationships between variables. Woody debris volume was positively correlated with drainage area (R=0.836; p=0.003) and flow (R=0.925; p=0.0001). HMFEI was positively 4 correlated with gradient (R=0.739, p=0.015) and taxa richness (R=0.943, p << 0.001). Percent EPT and taxa richness was positively correlated with median particle size (R=0.657, P=0.039; R=0.645, P=0.044). Ultimately, LWD volume did not impact bank stability, median particle size, or macroinvertebrates, suggesting that in the examined low gradient headwater streams, LWD is not the dominating factor in stream geomorphology or biology. However, gradient and median particle size were important variables in determining macroinvertebrate richness and abundance. Natural occurring LWD may not be as important in headwater streams as in larger streams, and calls to question the frequency that land managers are installing woody debris to increase macroinvertebrate biodiversity in headwater streams to mimic the natural system. This study adds to existing literature about intermittent headwater streams, however there is still a need to increase our understanding of the complex interactions that impact a stream’s macroinvertebrate diversity and susceptibility to erosion. 5 DEDICATION I would like to dedicate this thesis to my parents for teaching me to love the earth, and all who occupy it. 6 ACKNOWLEDGMENTS I would like to deeply thank the chair of my committee, Dr. Kelly Johnson for all of her help out in the field, and throughout the process of writing my thesis. I would also like to thank my committee members Dr. Natalie Kruse and Dr. Gregory Springer for all their assistance and constructive feedback. I would like to acknowledge all of those involved in the Appalachian Watershed Research Group (AWRG), particularly Jen Bowman, Dr. Dina Lopez, and Dr. Morgan Vis, as they offered valuable insight for my project as well. I would like to thank all of the professionals, undergraduate and graduate students that helped me collect data out in the field: Andrew Travers, Brandt Taylor, Brooke Stokes, Danding Gan, Lily Rudoff, Monica Ciszewski, Tate Pashibin, Tristan Hoffman, and Zeb Martin, without their help my thesis project wouldn’t have been possible. Finally, I would like to acknowledge the funding I received from the Voinovich School of Leadership and Public Affairs’ Appalachian Watershed Research Group’s American Electric Power Foundation Assistantship. 7 TABLE OF CONTENTS Page Abstract ............................................................................................................................... 3 Dedication ........................................................................................................................... 5 Acknowledgments............................................................................................................... 6 List of Tables ...................................................................................................................... 9 List of Figures ................................................................................................................... 10 Chapter 1: Introduction ..................................................................................................... 11 Chapter 2: Methods ........................................................................................................... 21 Study Area .................................................................................................................. 21 Study Sites .................................................................................................................. 21 Field Methods ............................................................................................................. 26 Quantification of woody debris ............................................................................ 26 Biological sampling .............................................................................................. 27 Median particle size .............................................................................................. 29 Bank stability ........................................................................................................ 30 Gradient and bank angle ....................................................................................... 31 Estimated stream power index and unit stream power ......................................... 33 Statistical Methods ...................................................................................................... 34 Chapter 3: Results ............................................................................................................. 36 Site Characteristics ...................................................................................................... 36 Correlations between Variables .................................................................................. 43 8 Linear Regression ....................................................................................................... 46 Chapter Four: Discussion .................................................................................................. 47 Woody Debris Volume Estimates in Headwater Streams .......................................... 47 Woody Debris Volume and Median Particle Size ...................................................... 50 Woody Debris Volume, FOM and Macroinvertebrate Indices ................................... 52 BEHI Score ................................................................................................................. 54 Chapter Five: Conclusion ................................................................................................. 56 References ......................................................................................................................... 58 Appendix A: Collected Macroinvertebrate Families ........................................................ 63 Appendix B: EURYCEA BISLINEATA Encountered At Each Site .................................. 67 Appendix C: Headwater Habitat Evaluation Index Sheets ............................................... 68 9 LIST OF TABLES Page Table 1. Study Site Characteristics and HUC- 12 Watershed ......................................... 25 Table 2. BEHI Scores and BEHI Categories among Sites ............................................... 42 Table 3. Correlations between Parameters ....................................................................... 45 10 LIST OF FIGURES Page Figure 1. Map of Study Sites ............................................................................................ 23 Figure 2. Sokkia™ CX-60 Series Total Station. ............................................................... 32 Figure 3. Woody Debris Volume per Site. ....................................................................... 36 Figure 4. Woody Debris Diameter Size per Site. .............................................................. 37 Figure 5.1 Drainage Area per Site. ................................................................................... 39 Figure 5.2 USGS Estimated Flow per Site. .....................................................................

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