Vegetation Based Assessment of Wetland Condition in the Prairie Pothole Region by Matthew Bolding A thesis presented to the University of Waterloo in fulfillment of thesis requirements for the degree of Master of Science in Biology Waterloo, Ontario, Canada, 2018 © Matthew Bolding 2018 Author’s Declaration I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii Abstract The northern prairie pothole region (NPPR) in central and southern Alberta contains numerous shallow, open-water pothole wetlands that provide important ecosystem services to the region, such as flood mitigation. To address the ongoing destruction of these systems, the Alberta government has put forth a new wetland policy to mitigate wetland loss and mandate wetland restoration to offset wetland loss. However, to evaluate the success of wetland restoration a tool is needed to assess wetland condition. An ideal tool for this management objective is a multimetric index (MMI). Multimetric ecological assessments such as the Index of Biotic Integrity use the responses of a specific biotic group as an indicator of disturbance, alleviating the need for complex direct measures of anthropogenic disturbance. Multimetric indices are used throughout the world to assess the condition of several ecosystems, and are applicable to wetlands. Wetlands in the NPPR have unique vegetation that is responsive to anthropogenic disturbance. I hypothesize that both the floristic attributes of wetland vegetation in this region and the distinct patterns of vegetation zonation could be used to produce a multimetric index that reliably indicates the condition of wetlands in agricultural areas. Seventy-two wetlands were sampled in central and southern Alberta in the summer of 2014 and 2015. Each wetland had its vegetation communities delineated and mapped using an SX Blue II GPS/GLONASS receiver to create spatial metrics. Vegetation quadrats were used to obtain floristic metrics related to percent cover, species richness and species traits. Using these metrics, I tested both the traditional method and random selection method of building an MMI. I successfully developed and validated MMIs for wetlands in central and southern Alberta using both floristic and spatial attributes of wetland vegetation. In addition, I was able to demonstrate that a random metric selection method, which allows metrics with weak relationships to disturbance to be incorporated generated a more sensitive MMI than the traditional method, which includes only the metrics most strongly related to disturbance. Both of these multimetric indices can be used to monitor wetland conditions and evaluate the success of wetland restoration projects in Alberta, directly addressing the needs of the government of Alberta to meet the conditions of their wetland policy. The spatial index is the first step in scaling towards a remote sensing approach in performing wetland assessments with an MMI. My work will assist wetland monitoring in Alberta and can be used to guide restoration practitioners in their efforts to create natural wetlands. iii Acknowledgements I would like to thank the Biology department at the University of Waterloo and the organizations that funded my research: Alberta Innovates – Energy and Environment Solutions. A huge thanks goes out to the land owners who graciously let us visit their wetlands many times, especially Rick & Deb who were gracious enough to feed us. I want to thank my committee members, Dr. Derek Robinson and Dr. Roland Hall who provided guidance and insight as I made my way through this research. Of course, I must thank my supervisor Dr. Rebecca Rooney without whom I wouldn’t have come close to finishing my thesis. While your expertise, patience, guidance and mentorship was important to me, your friendship was invaluable as I navigated the ups and downs of the past two years. I would like to thank the students of the Rooney lab for their help, and comradery throughout this project. Those of you who were involved in the field work: Adam Kraft, Daina Anderson, Graham Howell, Jenny Gleason, Heather Polan, and Nicole Meyers, our time in the (wet) trenches will not be forgotten. The Long Point team: Courtney Robichaud, Heather Polowyk, and Sarah Yuckin, thanks for listening to all my stories and hosting us for some great BBQ’s. To my family, thank you for believing in me and supporting me from afar while I worked, and sometimes struggled, through this. And a HUGE thanks to Courtney Robichaud who beyond anyone else, had my back throughout this and somehow knew I could do it, even when I had my doubts. iv Table of Contents Author’s Declaration ..................................................................................................................................... ii Abstract ........................................................................................................................................................ iii Acknowledgements ...................................................................................................................................... iv List of Figures ............................................................................................................................................. viii List of Tables ................................................................................................................................................ ix 1. General Introduction ............................................................................................................................. 1 1.1 The northern prairie pothole region and prairie pothole wetlands ................................................... 1 1.2 Wetland services & wetland loss ........................................................................................................ 2 1.3 Monitoring and assessment ................................................................................................................ 2 1.4 Assessment tools: multimetric index .................................................................................................. 4 1.5 Vegetation as an indicator .................................................................................................................. 7 1.6 Thesis objectives ................................................................................................................................. 9 2. Comparing methods of creating a multimetric index of wetland health using floristic vegetation metrics as indicators of disturbance ........................................................................................................... 10 2.1 Introduction ...................................................................................................................................... 10 2.1.1 Multimetric indices .................................................................................................................... 10 2.1.2 Development in metric selection techniques ............................................................................ 12 2.2 Methods ............................................................................................................................................ 15 2.2.1 Study sites .................................................................................................................................. 15 2.2.3 Disturbance Scores..................................................................................................................... 16 2.2.4 Stratified random assignation of sites into development and testing sets ............................... 17 2.2.5 Vegetation Sampling .................................................................................................................. 17 2.2.6 Data preparation ........................................................................................................................ 18 2.2.7 Metric Calculations .................................................................................................................... 19 2.2.8 Metric pre-screening .................................................................................................................. 19 2.2.9 MMI Development: Method 1 ................................................................................................... 20 2.2.10 MMI Development: Method 2 ................................................................................................. 20 2.2.11 MMI Selection .......................................................................................................................... 21 2.2.12 Metric Standardizing and Scoring ............................................................................................ 21 2.2.13 MMI Validation ........................................................................................................................ 22 2.2.14 Method Comparison ................................................................................................................ 22 2.2.15 Supplementary Tests ............................................................................................................... 23 2.3 Results ............................................................................................................................................... 23 v 2.3.1