The University of Maine DigitalCommons@UMaine Electronic Theses and Dissertations Fogler Library Spring 5-11-2019 Landscape Pattern and Wild Bee Communities in Maine Brianne Du Clos University of Maine, [email protected] Follow this and additional works at: https://digitalcommons.library.umaine.edu/etd Part of the Agricultural Education Commons, Agricultural Science Commons, Agronomy and Crop Sciences Commons, Apiculture Commons, Biodiversity Commons, Botany Commons, Entomology Commons, Fruit Science Commons, Integrative Biology Commons, Laboratory and Basic Science Research Commons, and the Terrestrial and Aquatic Ecology Commons Recommended Citation Du Clos, Brianne, "Landscape Pattern and Wild Bee Communities in Maine" (2019). Electronic Theses and Dissertations. 2970. https://digitalcommons.library.umaine.edu/etd/2970 This Open-Access Thesis is brought to you for free and open access by DigitalCommons@UMaine. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of DigitalCommons@UMaine. For more information, please contact [email protected]. LANDSCAPE PATTERN AND WILD BEE COMMUNITIES IN MAINE By Brianne Elizabeth Du Clos B.S. University of Wisconsin-Superior, 2009 M.S. University of Maine, 2012 A DISSERTATION Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy (in Ecology and Environmental Sciences) The Graduate School The University of Maine May 2019 Advisory Committee: Cynthia S. Loftin, Unit Leader, U.S. Geological Survey Maine Cooperative Fish and Wildlife Research Unit, Associate Professor of Wildlife Ecology, Co-Advisor Francis A. Drummond, Professor of Insect Ecology, Co-Advisor Dana Marie Bauer, Assistant Director and Research Scientist, George Perkins Marsh Institute, Clark University Alison C. Dibble, Assistant Research Professor of Pollination Ecology Samuel Hanes, Assistant Professor of Anthropology LANDSCAPE PATTERN AND WILD BEE COMMUNITIES IN MAINE By Brianne Elizabeth Du Clos Dissertation Co-Advisors: Dr. Cynthia S. Loftin and Dr. Francis A. Drummond An Abstract of the Dissertation Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy (in Ecology and Environmental Sciences) May 2019 Commercial production of lowbush blueberry (Vaccinium angustifolium Aiton) in Maine relies primarily on managed honeybee hives; however, naturally occurring wild bees are more efficient pollinators of the crop. Wild bees have short foraging distances and must nest near crop fields to provide pollination services. After crop bloom, the surrounding landscape must provide sufficient forage to maintain wild bee populations for the remainder of the growing season. Lowbush blueberries in Maine are produced in a mixed-use landscape with two distinct landscape contexts. Here, we document bee communities and habitat resources (nesting and floral) in power line rights-of-way and eight land cover types including and surrounding lowbush blueberry fields. We assess landscape pattern surrounding crop fields in the two contrasting contexts and determine any effect of arrangement of habitat patches on wild bee abundance or diversity. Additionally, we use our field data to inform and validate predictions of wild bee abundance from a spatial model applied to the lowbush blueberry production landscape and assess any influence of landscape pattern on prediction accuracy. Finally, we describe a collaboration with lowbush blueberry growers to develop an interactive web mapping tool that provides maps of habitat resources and predicted wild bee abundance. We documented 168 wild bee species across 72 study sites; three bee species had not been previously recorded in Maine. Power line rights-of-way had diverse and abundant bee communities owing to high habitat quality, especially within resource-poor landscapes near lowbush blueberry fields. We observed abundant floral resources in lowbush blueberry fields, forest edges, and small towns and found ample nesting resources in lowbush blueberry fields and shrubby wetlands. Bees were less abundant and diverse in a homogeneous landscape context; however, that homogeneity led to more accurate model predictions of bee abundance in crop fields. We improved prediction accuracy in a mixed-use landscape and produced accurate predictions in non-crop land cover types in a heterogeneous landscape context; however, we found that predictions of wild bee abundance in crop fields are influenced by landscape heterogeneity. The maps we share through the web tool aid growers and other stakeholders in developing pollination management and conservation plans. ACKNOWLEDGEMENTS This work was supported by the U.S. Department of Agriculture National Institute of Food and Agriculture – Specialty Crops Research Initiative Contract/Grant/Agreement No. 2011-51181-30673, Northeast Sustainable Agriculture and Research Education Grant GNE14- 076, a Senator George J. Mitchell Center for Sustainability Solutions – Sustainability Research Grant, the Wild Blueberry Commission of Maine, and the University of Maine and Maine Department of Inland Fisheries and Wildlife through the Cooperative Agreement with the U.S. Geological Survey Maine Cooperative Fish and Wildlife Research Unit. My co-advisors, Cyndy Loftin and Frank Drummond, have been incredible mentors. I am grateful for the guidance, patience, and expertise they provided in the development, execution, and completion of this work. I am especially appreciative of the time and effort they put in to continue providing for me as the years dragged on; it got a bit rough at times, but we finally did it. Working for them has been the best. I am grateful for the experiences I had working with each of my additional committee members: Dana Bauer, Alison Dibble, and Sam Hanes. Their expertise enriched and improved this work. Thank you to my student technicians for assistance in fieldwork and preparing collected specimens for identification: Jacob Eddy, Randi Jackson, Sam Kenney, Ellie McCarthy, Deanna Phipps, and Crystal Thomes. Thank you to Judy Collins and Elissa Ballman and their student technicians for assistance and collaboration in fieldwork and specimen preparation. Thank you also to the landowners for allowing me to sample bees and plants on their property. Thank you to the taxonomic experts who taught and assisted me in bee and plant identification: Sara Bushmann, Alison Dibble, Frank Drummond, Sam Droege, Jason Gibbs, and Rob Jean. Drs. Bushmann, Dibble, and Drummond created an engaging and enriching course at ii the Eagle Hill Institute that provided a very strong foundation for my nascent bee identification skills. I am also grateful to Sam Droege at the U.S. Geological Survey Native Bee Identification and Monitoring Lab for allowing me to spend a few days at the lab for a crash course in identification and specimen management. BeeMapper would not have been possible without an interdisciplinary collaborative development effort initiated and fostered by Sam Hanes. Dr. Hanes provided funding, found technical support, suggested growers to test the tool, and provided me with an incredible skill set that I am excited to take with me moving forward. Thank you so much. Rob Powell at the University of Maine underwent a herculean effort to assemble the technical infrastructure behind BeeMapper, and I am incredibly appreciative of his work. I am grateful to the University of Maine Cooperative Extension and the Advanced Computing Group for providing website space and server space for BeeMapper to live on. And finally, I am grateful to the growers who took the time to provide their input on the tool. BeeMapper would not be what it is without them. Thank you to my lab mates, office mates, colleagues, and friends at UMaine. Thank you to the Darling Marine Center for welcoming a landlubber for a couple of years and providing me with an incredible space to work. Thank you to the administrative staff of the Department of Wildlife, Fisheries, and Conservation Biology for being so wonderful. Most importantly, thank you to my family, for their unwavering support and unceasing encouragement as I chugged along through graduate school. You all are my ultimate motivation. iii TABLE OF CONTENTS ACKNOWLEDGEMENTS ............................................................................................................ ii LIST OF TABLES ...........................................................................................................................x LIST OF FIGURES ..................................................................................................................... xiv CHAPTER 1. WILD BEE COMMUNITIES IN POWER LINE RIGHTS OF WAY IN MAINE’S LOWBUSH BLUEBERRY PRODUCTION LANDSCAPE ........................................1 1.1. Introduction ...................................................................................................................1 1.2. Methods.........................................................................................................................3 1.2.1. Study area and spatial data .............................................................................3 1.2.2. Field sampling and site characteristics ..........................................................5 1.2.3. Statistical analyses .........................................................................................8 1.3. Results .........................................................................................................................10