Quantifying avian and forest communities to understand interdependencies of ecological systems and inform forest bird conservation Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Bryce Timothy Adams Graduate Program in Environment and Natural Resources The Ohio State University 2018 Dissertation Committee Stephen N. Matthews, Advisor Robert J. Gates Chris M. Tonra Laura J. Kearns Louis R. Iverson 1 Copyrighted by Bryce Timothy Adams 2018 2 Abstract Forests represent the largest terrestrial biome on Earth, providing a wealth of ecological and social services. Their effective conservation and management under intensifying anthropogenic threats, climate change, and shifting disturbance regimes hinges on an accurate knowledge of ecological process and spatial pattern to address questions related to their dynamics, how they are changing, and what resources they provide to wildlife. Predictive models are currently the main tools used to quantify landscape-level forest parameters and resource use of wildlife communities. Advances in remote sensing technologies and new, innovative ways to characterize these data offer great potential for improved quantification and monitoring of ecological systems. My overall research seeks to integrate new methodologies for landscape-level quantification of avian and forest communities and to investigate interrelationships that inform forest bird conservation in southeastern Ohio. The study area, positioned within the Central Hardwoods Region, displays a pronounced floristic gradient, recognized as one of the most speciose forested regions in the eastern US. I sampled avian and woody plant assemblages across a spectrum of forest stands with different vegetation composition and structure within six study sites during 2015 and 2016. My objectives include: (1) to determine the relative importance of plant taxonomic composition versus vegetation structure on the species composition of avian assemblages; (2) to examine the ii effectiveness of multi-sensor fusion of different remote sensing platforms that are sensitive to improved monitoring of forest successional state; (3) to incorporate concepts of community-continua to map floristic assemblages; (4) to develop predictive models of bird species abundance to map potential habitat quality for selected species and examine the importance of various remotely-sensible data attributes; and (5) to develop a community-level model of bird species composition and evaluate its efficacy in providing species-level inference. Collectively, my results help to reinforce (1) the importance of environmental heterogeneity in maintaining bird diversity within managed forests, (2) the many interdependencies among avian and floristic assemblages, and (3) the effectiveness of remote sensing platforms in quantifying ecological process and spatial pattern of forested landscapes. Many of the vegetation factors I examined, considered decisive in determining avian resources, were rarely independent. The strong individual and community-level responses of birds to forest compositional gradients can also be taken as a response to variation in structure among these different forest types, as vegetation structure and floristic composition were intimately related in most cases. But species- specific preferences for certain tree species and the integrative nature of plant composition data helped explain its strong predictive power for avian assemblage composition. Nonetheless, stand management aimed to manipulate structural complexity within and among forest stands will influence plant species composition in ways that meet the fine-scale resource needs of certain species. A diversity of growth stages can provide not only diverse vegetation structures, but also a diversity of tree species. The iii diversity and composition of understory shrubs should not be overlooked as well, as many forest birds utilize the understory strata for nesting and foraging. Foundational oak species (Quercus spp) will require special attention to ensure restoration of these species assemblages into the future. Policies should aim to maintain a diversity of stand types, in terms of structure, growth stage, and tree composition, to provide a range of habitat conditions for birds and other wildlife. Additionally, climate change is expected to impact forest communities in unpredictable ways. Full-stand taxonomic composition of forest stands of different type and structure should be frequently evaluated in the coming decades to ensure policies are successfully implemented to maintain environmental heterogeneity and desired levels of diversity. The methods I utilized show great potential for remotely inventorying the compositional patterns of forests at landscape extents. Restoration of important tree species can be greatly advanced by these methods to ensure viable species pools remain under shifting vegetation pressures. iv Dedication For Melissa and Maddie v Acknowledgments I would like to begin by especially thanking my advisor, Steve Matthews, for his commitment to me and this project. I owe a debt of gratitude to Steve for taking me on as a student. Steve allowed me to entertain a diversity of research topics and provided the support I needed at every step. He was an excellent mentor and a strong advocate for me. He greatly contributed to the person I am today. I would also like to acknowledge my committee for their support and encouragement throughout this project. Laura Kearns provided an invaluable perspective on the important conservation perspectives I often overlooked. Chris Tonra helped me focus on aspects of avian life history that I often neglected or didn’t consider. Louis Iverson provided encouragement every step of the way, valued my perspective, and contributed to opportunities for me to engage in broader research efforts. I spent a considerable amount of time with Bob Gates, serving as a TA for him for three semesters and assisting him with his quantitative methods class. I greatly appreciate the support he provided on this project and his consideration of me when opportunities arose in all aspects of my time as both an undergraduate and graduate student at Ohio State. I would also like to thank Bob for his championing of graduate education at Ohio State. I would like to acknowledge the agencies and people that were involved in this project. Funding support was provided by The Ohio State University, the Ohio vi Department of Natural Resources - Division of Wildlife administered through the Ohio Biodiversity Conservation Partnership and the US Fish and Wildlife Service. Additional support was provided by the Terrestrial Wildlife Ecology Laboratory. I especially would like to thank Steve Smith and Dennis Hull for their administrative and logistical support. I would also like to thank the School of Environment and Natural Resources for their support over the last four years. Several people of the US Forest Service: Northern Research Station provided additional logistical support, particularly Bill Borovicka and David Runkle. A special thank you goes out to Kaley Donovan who helped immensely in data collection and study design. Additional folks who braved the rugged terrain and tick- infested brush also deserve a special thank you: James Hanks, Garrett Evans, Sara Zaleski, Alex Eberts, and Daniel Hodges. I would like to thank the many graduate students that I spent time with in Kottman Hall over the last four years. Thanks for the companionship over the last four years! I would also like to recognize Bill Peterman for the many statistical and programming discussions we had, which helped to influence this research. Additionally, Anantha Prasad, Matt Peters, and Gabe Karns engaged in many discussions on statistics and GIS. I would like to recognize David Hix for helping me better appreciate the science of forest ecology and management and influencing my approach to teaching. I would like to thank my family for their support over the years in my choice of career. My mother and father have encouraged and supported me to pursue my ambitions throughout my life. I would be remised to not recognize my mother-in-law and father-in- vii law for their support as well, particularly for the many hours they spent babysitting my daughter. In closing, this work would not be possible without the support and understanding from my wife, Melissa, and the countless sacrifices she has made for me to pursue my professional aspirations. I am deeply indebted to her patience and tolerance throughout this journey. For this, I cannot describe how appreciative I am for her love and support. viii Vita 2010........................................B.S. Environment and Natural Resources (Major), Evolution and Ecology (Minor), The Ohio State University 2014........................................M.S. Biology, Bowling Green State University 2014-present ...........................Doctoral Student, School of Environment and Natural Resources, The Ohio State University Fields of Study Major Field: Environment and Natural Resources ix Table of Contents Abstract ............................................................................................................................... ii Dedication ........................................................................................................................... v Acknowledgments.............................................................................................................