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Item Geomorphology, biodiversity and ecosystem function, and food web dynamics in large riverscapes(Montana State University - Bozeman, College of Letters & Science, 2021) Scholl, Eric Arthur; Chairperson, Graduate Committee: Wyatt F. Cross; This is a manuscript style paper that includes co-authored chapters.Humans have transformed the Earth's surface so extensively that we now play a dominant role in regulating geomorphological processes around the world. These effects are particularly prevalent in large rivers, which despite their high biophysical complexity, face widespread habitat alteration and simplification. The way species respond to such changes will unquestionably impact the structure and function of ecosystems, with cascading effects on numerous goods and services they provide. Consequently, efforts to understand how the physical habitat template shapes the structure and function of larger river ecosystems are critically needed to predict how future perturbations will impact these imperiled and iconic environments. My dissertation blends approaches from the physical and ecological sciences to uncover connections between the geophysical habitat template, biodiversity and ecosystem function, and the dynamics of food webs in large riverscapes. My questions were: 1) what are the spatial patterns and potential drivers of riverbed habitat, and how do they relate to process domain structures in large rivers? 2) how does the geophysical habitat template influence connections between invertebrate diversity and secondary production? and 3) how are trophic interactions supporting the federally endangered Pallid Sturgeon (Scaphirhynchus albus) shaped by the geophysical habitat template? I found consistent patterns of nested patchiness in riverbed substrate, indicating that multiple factors operating at different scales influence spatial patterns of substrate in the Missouri and Yellowstone Rivers. Invertebrate assemblages were tied to attributes of the geophysical habitat template, with strong relationships between large sediments and diversity. Invertebrate diversity, in turn, was positively related to secondary production, with the most diverse assemblages found in secondary production 'hotspots'. Finally, I found a general relationship between habitat diversity and trophic interaction strengths supporting Pallid Sturgeon, with geophysically diverse areas containing much weaker, and thus potentially stabilizing, interactions than homogenous areas. Additionally, habitat characteristics, such as sediment size, intensified these effects. Together, the chapters of my dissertation broadly highlight the role of nature's stage in governing patterns in biodiversity, secondary production, and trophic interactions across large and dynamic riverscapes, and provide empirical insights for guiding future management and conservation of large rivers in an increasingly simplified world.Item Using noninvasive genetic sampling methods to estimate demographic and genetic parameters for large carnivore populations in the Rocky Mountains(Montana State University - Bozeman, College of Letters & Science, 2012) Sawaya, Michael Allen; Chairperson, Graduate Committee: Steven Kalinowski; Toni K. Ruth, Scott Creel, Jay J. Rotella, Jeffrey B. Stetz, Howard B. Quigley, and Steven T. Kalinowski were co-authors of the article, 'Evaluation of noninvasive genetic sampling methods for cougars in Yellowstone National Park' in the journal 'Journal of wildlife management' which is contained within this thesis.; Jeffrey B. Stetz, Anthony P. Clevenger, Michael L. Gibeau and Steven T. Kalinowski were co-authors of the article, 'Estimating grizzly and black bear population abundance and trend in Banff National Park using noninvasive genetic sampling methods' in the journal 'PLoS ONE' which is contained within this thesis.; Anthony P. Clevenger, and Steven T. Kalinowski were co-authors of the article, 'Wildlife crossing structures connect ursid populations in Banff National Park' in the journal 'Conservation biology' which is contained within this thesis.; Steven T. Kalinowski, and Anthony P. Clevenger were co-authors of the article, 'Gene flow at wildlife crossing structures in Banff National Park' in the journal 'Molecular ecology' which is contained within this thesis.Healthy carnivore populations are important to maintaining ecosystem balance, but many species are declining globally at disturbing rates due to anthropogenic causes. To effectively manage and conserve carnivores, wildlife managers must be able to obtain reliable estimates of population parameters. Noninvasive genetic sampling (NGS) methods such as hair or scat collection offer new and exciting alternatives to traditional carnivore research methods involving capture, drugging, and handling of animals; however, the potential of NGS methods to answer applied ecological questions has not been fully realized. The main objective of my doctoral research was to develop and apply NGS methods to estimate demographic and genetic parameters for large carnivore populations in the Rocky Mountains. First, I evaluated two NGS methods, hair snares and snow tracking, for cougars (Puma concolor) in Yellowstone National Park. I developed a method to collect hair while following cougar tracks in snow to bed sites and natural hair snags (e.g. thorn bushes, branch tips) from which I demonstrated that samples collected using NGS can provide reliable information on cougar population abundance. Next, I compared the ability of two NGS methods, hair traps and bear rub surveys, to estimate population abundance and trend of grizzly (Ursus arctos) and black bears (U. americanus) in Banff National Park. I found that bear rubs performed better than hair traps for estimating grizzly bear abundance and population growth rates, whereas hair traps worked better than bear rubs for black bears. I then used NGS to examine demographic and genetic connectivity at wildlife crossing structures along the Trans-Canada Highway that bisects Banff National Park. I compared genetic data collected from the bear populations surrounding the highway to data collected at the crossing structures using a novel hair sampling system. This comparison allowed me to show that wildlife crossing structures provided demographic connectivity for bear populations and maintained sufficient gene flow across the highway to prevent genetic isolation. In short, I have demonstrated the power of using an array of NGS methods, alone or in combination, to estimate abundance, gene flow, genetic structure, migration, and population growth rates for large carnivores in the Rocky Mountains.