Linking Microhabitat and Species Distributions Of
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Notes from the Underground: Linking Microhabitat and Species Distributions of Plethodontid Salamanders A dissertation presented to the faculty of the College of Arts and Sciences of Ohio University In partial fulfillment of the requirements for the degree Doctor of Philosophy Vincent R. Farallo April 2017 © 2017 Vincent R. Farallo. All Rights Reserved. 2 This dissertation titled Notes from the Underground: Linking Microhabitat and Species Distributions of Plethodontid Salamanders by VINCENT R. FARALLO has been approved for the Department of Biological Sciences and the College of Arts and Sciences by Donald B. Miles Professor of Biological Science Robert Frank Dean, College of Arts and Sciences 3 ABSTRACT FARALLO, VINCENT R., Ph.D., April 2017, Biological Sciences Notes from the Underground: Linking Microhabitat and Species Distributions of Plethodontid Salamanders Director of Dissertation: Donald B. Miles Environmental characteristics play a pivotal role in delineating species distributions and, in turn, influence species richness, diversity, and interspecific interactions. However, species exist at various spatial and temporal scales. Therefore, the scale at which environmental data is collected will influence the interpretations of how it impacts organisms. Most species primarily exist at a small spatial scale making broad- scale climate and habitat data often less biologically relevant to these organisms. Instead microhabitat and microclimate variables are often what species will directly experience, which makes the connection between macro- and micro-scale data important for answering evolutionary and ecological questions. This dissertation quantifies microhabitat and microclimate use of plethodontid salamanders across a broad geographic area including latitudinal and elevational gradients. First, I review the importance of micro-scale environmental data and how can bolster studies in evolutionary ecology. Next, I focus on species ability to choose specific microhabitat and microclimates including direct comparisons to habitat and climates that is available to captured salamanders, but remains unused. I found that salamanders were able to choose specific environmental conditions. Furthermore, species used different microhabitat and microclimates, including closely related species. To further refine our 4 knowledge of microhabitat and microclimate use, I include a study monitoring thermal and hydric properties of various microhabitats in the Great Smoky Mountains National Park along an elevational gradient. I found that they chose cooler and wetter microhabitats and that they chose microhabitats that maintain their hydric state even between high and low elevation sites, indicating that through behavioral compensation they may be able to extend their ranges beyond what broad-scale climate data predict. Finally, I tested for phylogenetic signal of these small-scale variables and found as whole there is no indication of phylogenetic signal. However, two individual variables relative humidity and soil temperature, have significant phylogenetic signal which appears driven by differences in the Plethodon cinereus and Plethodon glutinosus species groups. Together, these results provide a substantial contribution to our knowledge of the evolutionary ecology of plethodontid salamanders, and highlight the importance of incorporating small-scale environmental data, especially when assessing the impacts of climate change. 5 DEDICATION For my family, especially my grandfathers, Vincent Farallo and Robert E. Brogan, who taught me a love of learning and nature. 6 ACKNOWLEDGMENTS This dissertation was possible due in thanks too many people. My advisor, Donald Miles, who offered academic guidance throughout my dissertation. My dissertation committee, Shawn Kuchta, Willem Roosenburg, and James Dyer have also provided mentorship. Thank you to the Ohio Center for Ecology & Evolutionary Studies (OCEES) graduate students, postdocs, and faculty for the countless hours of discussion and feedback, especially current and former members of the Miles laboratory. The field work required to complete this dissertation would not be possible without help from numerous field assistants including William Ternes, Rebecca Wier, Celeste Wheeler, Morgan Etheridge, Kaili Boarman, Jessica Mace, and Courtney Thomas. Furthermore, the United States National Parks and National Forest Service allowed me access to field sites. A special thanks to Paul Super, the research coordinator of the Great Smoky Mountains National Park, who was an invaluable help throughout my dissertation. Financial support for this work was provided by Ohio University Student Enhancement Award, Ohio University GSS Original Work Grants, Sigma Xi GIAR, Explorer’s Club Exploration Fund Grants, Society for the Study of Evolution Rosemary Grant Award, and an American Philosophical Society Lewis and Clark Fund Award. I was also able to extend my field work in thanks to the OCEES and Ohio University Graduate College Fellowships. 7 TABLE OF CONTENTS Page Abstract ............................................................................................................................... 3 Dedication ........................................................................................................................... 5 Acknowledgments............................................................................................................... 6 List of Tables .................................................................................................................... 10 List of Figures ................................................................................................................... 11 Chapter 1: Seeing the Forest and Missing the Trees: The Role of Scale in the Ecology and Evolution of Species Distributions ................................................................................... 13 Introduction ................................................................................................................... 13 The Problem of Scale ................................................................................................ 16 Spatial-scale and Evolutionary History .................................................................... 30 Case Study: Examining the Habitat of Microendemics ............................................ 31 Conclusions ................................................................................................................... 38 Figures .......................................................................................................................... 39 Chapter 2: The Importance of Microhabitat: A Comparison of Two Microendemic Plethodon Species to the Widespread P. cinereus ............................................................ 44 Introduction ................................................................................................................... 44 Plethodontid Salamanders as a Model System ......................................................... 45 Material and Methods ................................................................................................... 51 Field Sites .................................................................................................................. 51 Microhabitat Measurements ...................................................................................... 51 Statistical Analyses ................................................................................................... 53 Results ........................................................................................................................... 54 Variation in Microhabitat Traits ............................................................................... 54 GLMM Analysis ....................................................................................................... 55 Temporal Change of Microhabitats .......................................................................... 56 Discussion ..................................................................................................................... 57 Tables ............................................................................................................................ 62 Figures .......................................................................................................................... 63 8 Chapter 3: Small-scale Habitat Use of Plethodontid Salamanders along the Appalachian Mountains ......................................................................................................................... 68 Introduction ................................................................................................................... 68 Materials and Methods .................................................................................................. 75 Field Sites .................................................................................................................. 75 Microhabitat Data Collection .................................................................................... 75 Statistical Analyses ................................................................................................... 78 Results ........................................................................................................................... 81 Discussion ....................................................................................................................