Ecology and Evolutionary Biology Commons^™

Effects Of Mountaintop Removal Mining On Population Dynamics Of Stream Salamanders, Sara B. Freytag

Theses and Dissertations--Forestry and Natural Resources

Mountaintop removal mining (MTR) is a notorious stressor of stream ecosystems in the Central Appalachians. Valley fills (VF) lead to reduced occupancy, abundance, and species richness of stream salamanders. Multiple factors may be responsible for these reductions, but specifically habitat fragmentation and degradation may reduce colonization rates and increase local extinction rates. From 2013-2015, repeated counts of salamanders were conducted in stream reaches impacted by MTR/VF and compared to counts in reference reaches to answer the question: do stream salamander population dynamics differ between stream reaches impacted by MTR/VF and reference stream reaches? I also investigated dynamics of stream habitat …

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. …

Investigations In Cryptic Species: Considerations And Applications For Estimating Detection, Occupancy, And Abundance Of Semi-Aquatic Snakes, Christian Robert Oldham

Theses and Dissertations--Forestry and Natural Resources

Snake species are notoriously difficult to study in the field due to their cryptic natural-histories and secretive behaviors. Difficulties associated with detection present challenges estimating parameters including occupancy and abundance, as well as responses to habitat degradation. Our objectives were to use Passive Integrated Transponder (PIT) telemetry to enhance detection of Queensnakes (Regina septemvittata) as compared to traditional capture-mark-recapture (CMR) survey techniques and to examine occupancy and abundance of Queensnakes and Northern Watersnakes (Nerodia sipedon) in streams of differing levels of anthropogenic impact within Central Kentucky. During 2013, we captured Queensnakes and implanted them with PIT …

Ecology Of Two Reintroduced Black Bear Populations In The Central Appalachians, Sean Mccarthy Murphy

Theses and Dissertations--Animal and Food Sciences

Reintroduced populations are vulnerable to demographic and environmental stochasticity, deleterious genetic effects, and reduced population fitness, all of which can increase extinction probability. Population viability is principle to determining the status of reintroduced populations and for guiding management decisions. To attempt to reestablish black bear (Ursus americanus) populations in the central Appalachians, two reintroductions using small founder groups occurred during the 1990s in the Big South Fork area along the Kentucky-Tennessee border (BSF) and in the Jefferson National Forest along the Kentucky-Virginia border (KVP). My objectives were to estimate demographic and genetic parameters, and to evaluate long-term viability …

Transcriptional Regulation Of Specialized Metabolites In Arabidopsis Thaliana And Catharanthus Roseus, Craig M. Schluttenhofer

Theses and Dissertations--Plant and Soil Sciences

For millennia humans have utilized plant specialized metabolites for health benefits, fragrances, poisons, spices, and medicine. Valued metabolites are often produced in small quantities and may command high prices. Understanding when and how the plant synthesizes these compounds is important for improving their production. Phytohormone signaling cascades, such as jasmonate (JA) activate or repress transcription factors (TF) controlling expression of metabolite biosynthetic genes. TFs regulating specialized metabolite biosynthetic genes can be manipulated to engineer plants with increased metabolite production.

WRKY transcription factor are known components of both JA signaling cascades and regulation of specialized metabolism. The presence of WRKY binding …

Population Genetic Structure Of Necturus Maculosus In Central And Eastern Kentucky, Mason Owen Murphy

Theses and Dissertations--Biology

Population structure is influenced by extrinsic factors, such as landscape architecture and dispersal barriers. Lotic network architecture is known to constrain ecological, demographic and evolutionary processes, including population genetic structure. I assessed the population structure of a widespread aquatic salamander, Necturus maculosus, across three river basins in central and eastern Kentucky. I examined the role of network architecture, anthropogenic barriers, and spatial scale on patterns of population structure. I also provided a review of N. maculosus capture methods and offer an improved trap design. I identified significant structuring between the combined Licking/Kinniconick basin and the Kentucky River basin, with …

Influence Of Structural Disturbance On Stream Function And Macroinvertebrate Communities In Upper Coastal Plain Headwater Streams, Richard Andrew Biemiller

Theses and Dissertations--Entomology

Freshwater is a resource under threat due to anthropogenic actions. Stream restoration is a common method for mitigating disturbance. Inconsistent methodologies used for evaluating restorations have drawn criticism. Limited use of baseline data for guiding stream restoration activities is of particular concern. This study was developed to elucidate metrics that differentiate reference and disturbed sites in Upper Coastal Plain streams. This information could improve resource use and successes of restorations. Structural and functional variables were examined in 10 reference and 10 streams that meet the traditional definition of disturbance and would be restoration priorities. Disturbed streams were classified into two …