(Title of the Thesis)*
Total Page:16
File Type:pdf, Size:1020Kb
Rethinking restoration ecology of tallgrass prairie: considering belowground components of tallgrass restoration in southern Ontario by Heather Anne Cray A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Doctor of Philosophy in Social and Ecological Sustainability Waterloo, Ontario, Canada, 2019 ©Heather Anne Cray 2019 Examining Committee Membership The following served on the Examining Committee for this thesis. The decision of the Examining Committee is by majority vote. External Examiner Dr. Andrew MacDougall Associate Professor, Guelph University Supervisor(s) Dr. Stephen Murphy Professor & Director, University of Waterloo Internal Member Dr. Andrew Trant Assistant Professor, University of Waterloo Internal-external Member Dr. Rebecca Rooney Assistant Professor, University of Waterloo Other Member(s) Dr. Greg Thorn Associate Professor, Western University ii Author's Declaration This thesis consists of material all of which I authored or co-authored: see Statement of Contributions included in the 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. iii Statement of Contributions This thesis contains five chapters that are collaborative efforts of multiple researchers that will be submitted into peer-reviewed journals. Heather Cray is first author on all contributing papers and therefore was responsible for the development, data collection, data analysis and preparation of each of the manuscripts found in this dissertation. The written portions of all manuscripts, including figures and tables, were completed in their entirety by Heather Cray and edited for content and composition by thesis supervisor Dr. Stephen Murphy and committee members Dr. Andrew Trant, Dr. Greg Thorn, Dr. Rebecca Rooney, and Dr. Andrew MacDougall. Design, development, data collection, vegetation and soil analysis, and writing, including figures and tables, of chapter 4 was done by Heather Cray. The microbial data processing for chapter 4 was done by Dr. Josh Neufeld’s lab at cost through a contract and he assisted with the microbial analysis methods section for chapter 4; Dr. Neufeld will be an author on the journal manuscript resulting from that study. iv Abstract Agriculture, urban development, and woody encroachment have reduced the North American tallgrass prairie ecosystem to less than 1% of its historical extent. The remnants of this now rare habitat are currently challenged not only by ongoing human disturbance but by the anticipated ecological regime shifts from anthropogenic climate change. In response, active restoration of tallgrass prairie is ongoing, aiming to re-establish native vegetation communities, often on former croplands. The success of tallgrass prairie restoration has been mixed and many knowledge gaps exist, especially pertaining to soil biota. With the goal of addressing key knowledge gaps identified by restoration practitioners, this thesis investigates the invasive earthworm populations of restored and remnant tallgrass prairie sites across southern Ontario, establishes the dietary preferences of the largest and most widespread invasive earthworm Lumbricus terrestris with respect to seeds commonly used in tallgrass prairie restoration, and examines below-ground (soil bacterial community) as well as traditional above-ground (vegetation community) measures of restoration success for different methods of tallgrass prairie restoration. The core significant original contributions of this dissertation are 1) invasive earthworms are present and abundant in all remnant and restored tallgrass prairies in southern Ontario; 2) the largest and most widespread invasive earthworm, Lumbricus terrestris, can play an important role in seed granivory in tallgrass prairie habitats, and these effects are uneven across the target and weed species investigated; and 3) above- and below-ground measures of restoration success can tell different stories, and conventional restoration methods do not maintain microbial communities similar to high quality remnant prairie in the short term, whereas sod mat transplants do. Recommendations for practice include considering interactions with invasive earthworms in restoration and ecosystem management plans, considering alternative measures and methods of tallgrass prairie restoration, and broadening the definition of restoration success to encompass the retention and restoration of below-ground ecosystem components. By deliberately engaging the end-users of this research in question development and producing and communicating context-specific results and recommendations that can guide future management decisions, this dissertation is in line with the core tenants of translational ecology, which is suggested as a way forward for the discipline of restoration ecology. v Acknowledgements I am grateful to the Natural Sciences and Engineering Research Council of Canada and the rare Charitable Research Reserve for their financial support of this research. I would also like to thank Robert M. and Doreen M. Davis as well as Dean and Rose Ann Mutrie for establishing scholarships within the Faculty of Environment. I would also like to thank the rare Charitable Research Reserve, Conservation Halton, the Fadden family, Ontario Parks, the Ministry of Natural Resources and Forestry, the Ministry of Transportation, AMEC Foster Wheeler, Waynco, the Nature Conservancy of Canada, the Grand River Conservation Authority, and the Lower Thames Valley Conservation Authority for permitting me to access their properties, and several undergraduate volunteers for their assistance in the field. In particular, I would like to thank Corina Brdar, Phil Careless, and Darryl Mitchell of Ontario Parks and the Ministry of Natural Resources and Forestry; Barbara Macdonell of the Ministry of Transportation Ontario; Nigel Finney of Conservation Halton; and Season Snyder, Steve Marks, Russ Jones, Said Mohamed, and Peter Andrew-McBride of AMEC Foster Wheeler for their assistance with site access, safety training, permitting, and site histories. This thesis and my growth as a researcher benefitted from conversations with these land owners, practitioners, and managers. This work would not have been possible without the guidance of my thesis committee, including Dr. Andrew Trant, Dr. Greg Thorn, and Dr. Rebecca Rooney. Your input and feedback made this thesis a more comprehensive and compelling work and I appreciate the time you dedicated to helping me succeed. I would also like to thank my supervisor Dr. Stephen Murphy, who has supported my research direction and growth as a scientist and academic. Without him, this research would not have happened. I am also thankful to Dr. Josh Neufeld and lab manager Katja Engel for partnering with me to bring the microbial project to fruition and for their guidance on the microbial analysis process. I am grateful to Dr. Michael Drescher and Dr. Brendon Larson for serving on my comprehensive examination committee and suggesting publications to review, and to Dr. Andrew MacDougall for serving as my external examiner. During the PhD program I was fortunate to be encouraged by many friends and family, including my parents, grandmother, aunts, uncles, cousins, sister, niece, brother, and sister-in-law, as well as my UW family including fellow lab members Gwyn Govers, Patricia Hyunh, Jonas Hamberg, Amanda Shamas, and Tomm Mandryk. I also received incredible support from my long-time friends Emily Clarke, Heather Orr, and Anne Summerhays as well as my barn posse who were always there to cheer me on. I would also like to thank my partner-in-PhD Michael McTavish for his support and his willingness to bounce ideas around with me over hikes, meals, and Frisbee. I would also like to thank the staff and volunteers at the Ecology Lab of Waterloo, and in particular Bev Raimbault and Anne Grant, for providing the space and equipment necessary to process my soil samples, and always being happy to let me take over half of the lab. I was fortunate to do my PhD in a department full of wonderful staff and mentors. My growth as a researcher and scientist has been furthered by conversations with administrator Jennifer Nicholson, and Drs. Christine Barbeau, Simon Courtenay, Brad Fedy, Robert Gibson, Dan McCarthy, Brendon Larson, Rob de Loë, Andrea Collins, Maren Oelbermann, Sarah Wolfe, Derek Armitage, Ian Rowlands, and Stephen Quilley. vi Table of Contents Examining Committee Membership ....................................................................................................... ii Author's Declaration .............................................................................................................................. iii Statement of Contributions .................................................................................................................... iv Abstract………………………………………………………………………………………………………………………v Acknowledgements ............................................................................................................................... vi Table of Contents ................................................................................................................................. vii List of Figures ....................................................................................................................................... xi List of Tables .......................................................................................................................................