Evaluating and Monitoring the Success of Ecological Restoration Implemented by the University of Washington Restoration Ecology Network (UW-REN) Capstone Projects Joy Kristen Wood A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science University of Washington 2011 Program Authorized to Offer Degree: School of Forest Resources University of Washington Graduate School This is to certify that I have examined this copy of a master‟s thesis by Joy Kristen Wood and have found that it is complete and satisfactory in all respects, and that any and all revisions required by the final examining committee have been made. Committee Members: ___________________________________________________ James L Fridley __________________________________________________ Kern Ewing __________________________________________________ Warren G. Gold Date:__________________________________ In presenting this thesis in partial fulfillment of the requirements for a master‟s degree at the University of Washington, I agree that the Library shall make its copies freely available for inspection. I further agree that extensive copying of this thesis is allowable only for scholarly purposes, consistent with “fair use” as prescribed in the U.S. Copyright Law. Any other reproduction for any purposes or by any means shall not be allowed without my written permission. Signature ________________________ Date ____________________________ University of Washington Abstract Evaluating and monitoring the success of ecological restoration implemented by the University of Washington Restoration Ecology Network (UW-REN) capstone projects Joy Kristen Wood Co-Chairs of the Supervisory Committee: Professor James L. Fridley School of Forest Resources Professor Kern Ewing School of Forest Resources For every year since 2000, five to ten ecological restoration sites have been implemented in the Puget Sound region through the University of Washington Restoration Ecology Network (UW-REN) capstone program. These sites represent the integral cooperation necessary to facilitate successful restoration, as faculty, students, and community partners participate. Thirty sites were chosen for this study and evaluated for success across different parameters. I hypothesized that certain elements of restoration design and implementation, such as selected techniques for invasive vegetation suppression and removal, and the degree of site maintenance and stewardship strongly contribute to the success of these restoration sites. From the available documentation and field methods, information was gathered to conduct statistical analyses of the plant cover with respect to five explanatory variables: ownership, stewardship, initial invasive plant control technique, use of cardboard, and use of wood chip mulch. Ownership, stewardship, and control technique contribute significantly to the native composition, species richness, and species diversity of these restoration sites. Privately owned sites have greater native species composition than county and state owned sites, and city sites are more likely to have greater native species composition than state owned sites. High levels of stewardship result in greater native species composition than low stewardship, and mowing does not work as well as grubbing for initial invasive plant control technique in the outcome of native species composition. The use of cardboard and wood chip mulch is less clear. In the end, while stewardship is of the utmost importance in successful restoration, initial control technique and the use of mulch should also be considered important in determining the resulting native species composition. The use of cardboard should be considered carefully, weighing the benefits of deploying the resources to acquire the cardboard against the only slight benefit it seems to offer the outcome of native species composition. Different vegetative layers vary in their relationship with native and non-native cover, with trees being positively correlated and tall shrubs negatively correlated to native composition. TABLE OF CONTENTS Page List of Figures…………………………………………………………………………….. ii List of Tables…………………………………………………………………………...…iii 1.0 Introduction……………………………………………………………………………1 2.0 Literature Review……………………………………………………………………...4 2.1 Successional Trajectories……………………………………………………...4 2.2 Monitoring and Stewardship…………………………………………………..5 2.3 Invasive Species……………………………………………………………….7 2.4 Ecological Function and Native Biodiversity…………………………………9 3.0 Methods………………………………………………………………………………12 3.1 Site Selection…………………………………………………………………12 3.2 Document Review…………………………………………………………….13 3.3 Field Measurements…………………………………………………………..16 3.4 Canopy Cover………………………………………………………………….17 3.5 Data Analysis…………………………………………………………………19 4.0 Results………………………………………………………………………………...21 4.1 Project Goals…………………………………………………………………21 4.2 Ecological Evaluation Results………………………………………………..22 4.3 Site Management and Initial Restoration Technique…………………………28 4.4 Vegetative Cover at Various Layers………………………………………….32 4.5 Species Diversity……………………………………………………………..35 5.0 Discussion…………………………………………………………………………….38 5.1 Project Goals………………………………………………………………….38 5.2 Ecological Findings…………………………………………………………...39 5.3 Management and Technique…………………………………………………..42 5.4 Monitoring and Recommendations……………………………………………46 References………………………………………………………………………………….48 Appendix…………………………………………………………………………………...54 A. Applications and Lessons Learned……………………………………………..54 B. Site Summaries…………………………………………………………………56 C. Monitoring Protocol…………………………………………………………….92 D. Species Codes………………………………………………………………….101 i LIST OF FIGURES Figure Number Page 1. Sites Selected………………………………………………………………….13 2. Canopy Cover…………………………………………………………………18 3. Canopy Cover Values…………………………………………………………26 4. Cover and Explanatory Values………………………………………………..29 5. Multiple Regression Tree………………………………………………………31 6. Correlations…………………………………………………………………….32 7. Nonmetric Multidimensional Scaling (NMDS)………………………………..33 8. NMDS Canopy Cover………………………………………………………….34 9. NMDS Tree Cover……………………………………………………………..34 10. NMDS Vegetation Layers……………………………………………………..35 11. Species Richness and Diversity………………………………………………..37 12. Earth Sanctuary 2005…………………………………………………………..61 13. Frink Park 2002………………………………………………………………...67 14. Grass Lawn Park 2003………………………………………………………….69 15. Swamp Creek 2006……………………………………………………………..77 16. Swamp Creek 2007……………………………………………………………..79 17. West Duwamish Greenbelt 2006……………………………………………….88 ii LIST OF TABLES Table Number Page 1. Site Summary…………………………………………………………………..15 2. Explanatory Variables………………………………………………………….16 3. Project Goals…………………………………………………………………...22 4. Vegetation Abundance…………………………………………………………24 5. Regenerating Trees……………………………………………………………..27 6. Explanatory Variables ANOVA and Multiple Comparisons…………………..30 7. Species Richness and Diversity ANOVA and Multiple Comparisons…………36 8. Recommendations………………………………………………………………54 9. Site Composition Summary…………………………………………………….56 iii ACKNOWLEDGEMENTS I am grateful to my advisor, Jim Fridley, co-chair, Kern Ewing, and committee member, Warren Gold for their advice and guidance on this project. I would like to thank and acknowledge my invaluable and intrepid field assistants Ann Stevens, Lara Ramey, Mia Cole, and Jeremy Cairns for sticking it out with me at the restoration sites. Thank you to Rodney Pond for making available to me the project documentation. This project would not have been possible without the statistical advice I received from Aditya Khanna, Dev Niyogi, Joowon Park, and Jon Bakker. Thank you to those who supplied comments and revisions, help and support, and occasional babysitting: Kelsey Ketcheson, Ann West, Ann Stevens, Patti Wood, Brian Collins, Meredith Gilbert, and Marie-France Minton. And finally I would like to thank and acknowledge the endless support and encouragement from my best friend and husband, Stephen Wood, and Cameron Wood for her enduring patience with Mommy. 2 1.0 INTRODUCTION In 1999 the UW-REN program was established in order to integrate students, faculty and community interests in ecological conservation and restoration (Gold et al. 2006). For every year since 2000, five to ten restoration sites have been established in cooperation with a community partner, usually a non-profit organization, private land stakeholder, or governmental agency. Many of the restoration sites lie in urban, suburban, and rural areas such as the West Duwamish Greenbelt, Union Bay Natural Area, and Licton Springs in the Seattle area, Swamp Creek in Snohomish County, and the Earth Sanctuary on Whidbey Island. They include forested wetlands, streams, and upland forest habitats. The restoration sites varied in their land use context, ecological challenges, treatments used, and expectations for restoration. Each community partner submitted a request for proposal (RFP) outlining their restoration goals. Then the students accommodated those requests by designing a restoration plan that addressed the goals suggested in the RFP, considered the ecological state of the area as determined by a site assessment, and worked within the constraints of the team expertise, time, and available resources. Each restoration plan had specific goals and objectives in order to bring the site to a state of restoration, and the capstone students performed the first stages of restoration for the community partner. Various approaches were used, as the needs, goals, and challenges of each restoration site were unique. The students