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Item Aquatic Macroinvertebrate Response to Shifts in Hydroclimatic Variability and Ecohydrological Conditions in Prairie-Pothole Wetlands: Implications for Biodiversity Conservation(North Dakota State University, 2020) McLean, Kyle IanEcosystem degradation and subsequent biodiversity loss has plagued freshwater environments globally. Wetland ecosystems, such as the depressional wetlands found in the Prairie Pothole Region of North America, have been heavily impacted by historical land-use change and continue to be vulnerable to continued landscape modifications and climate change. Using existing literature, I summarized how recent shifts in climate coupled with historic and contemporary landscape modifications have driven a shift in wetland ecohydrological variability. However, clear trends in biodiversity were often limited by the spatial and temporal resolution of published research. I used 24 years (1992–2015) of hydrologic and aquatic-macroinvertebrate data from a complex of 16 prairie-pothole wetlands located in North Dakota to relate wetland ecohydrological variability to biodiversity. I used structural equation modeling techniques to test a set of causal hypotheses linking a wetland’s hydrogeologic setting and local climate conditions (i.e., the Wetland Continuum) to changes in hydrology, water chemistry, and biology, with an emphasis on aquatic-macroinvertebrate community response. I then examined the temporal synchrony of aquatic-macroinvertebrate populations to examine the relative importance of landscape-scale controls (e.g., climate, metacommunity dynamics) and wetland-specific controls on community assembly. Using this information, I then quantified among-wetland and amongyear changes in aquatic-macroinvertebrate beta diversity to investigate patterns of biotic homogenization. I found that spatial and temporal variability in aquatic-macroinvertebrate composition was strongly influenced by ponded-water dynamics. In addition to hydrologic controls, the high levels of temporal coherence of aquatic-macroinvertebrate compositional turnover supported the hypothesis that wetland biodiversity is also dependent on metacommunity dynamics. Analyses of spatio-temporal patterns in beta diversity did not reveal climate driven homogenization of aquatic-macroinvertebrate taxa among wetlands. However, shifts towards more permanently ponded water regimes corresponded with lasting shifts in aquatic-macroinvertebrate community composition. The communities of temporarily ponded wetlands maintained high levels of both temporal and spatial beta diversity. My collective findings indicate that the conservation of aquatic-macroinvertebrate diversity is dependent on the conservation of heterogenous, wellconnected, wetland complexes.Item The "Fathead Minnow Factory": Exploring How a Changing Climate Has Influenced Fish and Salamander Communities in the Prairie Pothole Region(North Dakota State University, 2015) McLean, Kyle IanGlobal climate change has been linked to changing many ecosystem processes. Early literature on climate change and biological systems predominately focused on individual species responses to temperature gradients. However, altered precipitation patterns can impact the ionic concentrations of aquatic habitats and thus affect the structure of entire communities. Understanding indirect effects of climate change, will be important to predict how whole systems have and will continue to change. Prairie pothole wetlands are well suited to study these processes. Prairie pothole wetlands are typically closed systems with natural hydrological fluctuations that have molded plant and wildlife communities adapted to these changing environments. However, a 20-year wet climate cycle has increased the permanency of many waterbodies facilitating colonization of various fish species, including the fathead minnow (Pimphales promelas). Thus, it is important to understand the environmental and biological aspects of prairie pothole wetlands facilitate fish presence under current and projected climate cycles.