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Full-Text Articles in Ecology and Evolutionary Biology

Residual Spatial Autocorrelation In Macroecological And Biogeographical Modeling: A Review, Guetchine Gaspard Jan 2021

Residual Spatial Autocorrelation In Macroecological And Biogeographical Modeling: A Review, Guetchine Gaspard

Theses and Dissertations--Geography

Macroecological and biogeographical modelers have predicted the distribution of species across space relying on the relationship between biotic processes and environmental variables. Such a method employs data associated, for instance, with species abundance or presence/absence, climate, geomorphology, and soils. Statistical analyses found in previous studies have highlighted the importance of accounting for the effects of spatial autocorrelation (SAC), which indicates a level of dependence between pairs of nearby observations. A consensus has existed that residual spatial autocorrelation (rSAC) can substantially impact modeling processes and inferences. However, more emphasis should be put on identifying the sources of rSAC and the degree …


Fluvial-Lacustrine Processes Shaping The Landforms Of The Distal Paraguay Fluvial Megafan, Edward Limin Lo Jan 2017

Fluvial-Lacustrine Processes Shaping The Landforms Of The Distal Paraguay Fluvial Megafan, Edward Limin Lo

Theses and Dissertations--Earth and Environmental Sciences

Tropical wetlands such as the Pantanal help regulate global biogeochemical cycles, but climate change is modifying these environments. Controls on environmental changes can potentially be assessed from ancient, well-dated lacustrine sedimentary records. An integrated field and laboratory approach was undertaken to study the limnogeology of Lake Uberaba in the northern Pantanal, and test whether the lake has preserved a reliable record of environmental change in its strata. This study was designed to understand how the basin accumulates sediment and to assess its sensitivity to hydroclimatic variability. The data showed that modern Lake Uberaba is a highly dynamic, freshwater fluvial-lacustrine basin. …


Effects Of Epichloë Coenophiala−Tall Fescue Symbiosis On Plant-Microbe-Soil Interactions In A Temperate Pasture, Lindsey C. Slaughter Jan 2016

Effects Of Epichloë Coenophiala−Tall Fescue Symbiosis On Plant-Microbe-Soil Interactions In A Temperate Pasture, Lindsey C. Slaughter

Theses and Dissertations--Plant and Soil Sciences

Plants interact in myriad ways with microorganisms to influence ecosystem processes such as nutrient cycling, which can regulate ecosystem response to global change. One important plant-microbe symbiosis occurs between cool-season grasses and asexual fungal Epichloë endophytes, such as tall fescue (Schedonorus arundinaceus) and Epichloë coenophiala. Because the common toxic strain of the endophyte (CTE) harms grazing livestock, non-livestock toxic endophyte (NTE) strains have been developed and are increasingly deployed in pastures. Little is known about how these symbioses impact other plant-microbe interactions and microbe-mediated soil processes in grassland ecosystems. I conducted three studies to determine how E. …


Ecohydraulic Investigation Of Diatoms In A Bedrock-Controlled Stream, Alex M. Rittle Jan 2015

Ecohydraulic Investigation Of Diatoms In A Bedrock-Controlled Stream, Alex M. Rittle

Theses and Dissertations--Geography

Recent studies within the past decade or so have shown the importance of algae in geomorphic and hydrologic processes of lotic systems. However, the ecohydraulic role of algae in bedrock systems has largely been ignored. In addition, the utility of algae as indicators of channel dynamics have often been assumed by geomorphologists, but relatively few studies have examined this relationship. The purpose of this study was to determine whether algae, specifically diatoms, are useful indicators of channel geomorphological dynamics, and to examine if distinct habitats or biotopes typical in fluviokarst and bedrock systems provide unique habitat space for diatoms, and …


Factors Influencing The Establishment And Survival Of Native Hardwood Tree Seedlings Of The Kentucky Inner Bluegrass Blue Ash-Oak Savanna-Woodland, James D. Shaffer Jan 2013

Factors Influencing The Establishment And Survival Of Native Hardwood Tree Seedlings Of The Kentucky Inner Bluegrass Blue Ash-Oak Savanna-Woodland, James D. Shaffer

Theses and Dissertations--Biology

Historically, the Kentucky Inner Bluegrass blue ash-oak savanna-woodland was the primary ecosystem of the Inner Bluegrass Region (IBR) of Kentucky. After European settlement, the majority (>99%) of Bluegrass savanna was converted to agricultural and urban land uses. Currently remnant savanna tree species are failing to recruit. Therefore, a long-term restoration ecology project researching competition and disturbance on seedling establishment, survival, and growth has been established at Griffith Woods (the largest remaining savanna in Kentucky) in Harrison Co., KY. Fourteen native hardwood tree species (a total of 6,168 seedlings) have been experimentally planted. Light, soil, surrounding vegetation, and herbivory, factors …