Life Sciences Commons^™

Bee Communities On Managed Emergent Wetlands In The Lower Mississippi Alluvial Valley Of Arkansas, Phillip Lee Stephenson

Graduate Theses and Dissertations

Native bee communities that use emergent wetlands are among the least studied systems in bee research. Most native bee species are thought to be in decline based on the loss of usable habitat across the United States. I surveyed emergent wetlands in the lower Mississippi Alluvial Valley of Arkansas during the summers of 2015 and 2016 using pan traps, blue-vane traps, and sweep nets to determine the current status of bee communities in this system. I surveyed 11 sites in 2015 and 17 sites in 2016 and found that bee communities were similar in actively versus passively managed emergent wetlands. …

Effects Of Wave Action On The Structure Of Fish Assemblages Across An Exposure Gradient, Lauren Liddon

Master's Theses

Disturbance affects the function and diversity of ecosystems. Increased wave exposure to salt marsh can disturb sediments and cause a loss of habitat. The purpose of this study was to explore the effects of increased wave exposure on diversity, abundance, and functional ecology of estuarine fishes. If increased wave exposure is acting as a disturbance to these habitats, ecological theory (Intermediate Disturbance Hypothesis) predicts that diversity will peak at intermediate frequencies and intensities of disturbance. Fish were sampled from 10 sites monthly for 6 years. The sites were assigned to different exposure categories (Open, Intermediate, and Sheltered) using an exposure …

Microbial Community Richness Distinguishes Shark Species Microbiomes In South Florida, Rachael Cassandra Karns

HCNSO Student Theses and Dissertations

The microbiome (microbial community) of individuals is crucial when characterizing and understanding processes that are required for organism function and survival. Microbial organisms, which make up an individual’s microbiome, can be linked to disease or function of the host organism. In humans, individuals differ substantially in their microbiome compositions in various areas of the body. The cause of much of the composition diversity is yet unexplained, however, it is speculated that habitat, diet, and early exposure to microbes could be altering the microbiomes of individuals (Human Microbiome Project Consortium, 2012b, 2012a). To date, only one study has reported on microbiome …

Bacterial Community Ecology Of The Colon In Mus Musculus, Rachel Marie Nettles

Theses and Dissertations

The gut microbiome is a community of closely interacting microbes living in the gastrointestinal tract. Its structure has direct relevance to health. Disturbances to the microbiome, such as due to antibiotic use, have been implicated in various diseases. The goal of this study was to determine how the gut microbiome reacts to and recovers from disturbance caused by antibiotics. Because diet also influences the microbiome, this study included the interaction between diet and antibiotics. Half of the mice in each diet treatment were given antibiotics to disturb their microbiomes. After cessation of antibiotics, mice were paired in combinations within diets …

Effects Of Variable And Changing Environments On Demography: Inferences From A Lesser Snow Goose Colony, David T. Iles

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mean and variability of environmental conditions have changed as a result of human activity, and continued changes are predicted. The strongest effects on natural populations will often be channeled through species interactions, as shifts in species range limits and life cycle schedules will shift in relation to each other. These changes will often impact rates of survival, growth, and reproduction simultaneously, and these effects will likely differ across habitats.

In chapter 2, I used mathematical modeling and computer simulations to investigate the evolutionary significance of increasingly variable environments, and examine how evolutionary pressures change when multiple vital rates are …

Conceptualizing And Measuring Food Security Among Resettled Refugees Living In The United States, Hannah Stokes

Graduate College Dissertations and Theses

Food security research with resettled refugees in the United States and other Global North countries has found alarmingly high rates of food insecurity, up to 85% of surveyed households. This is well above the current US average of 12.7%. However, the most common survey tool used to measure food security status in the US, the US Household Food Security Survey Module (HFSSM), has not been sufficiently validated for resettled refugee populations, leading to the risk that the HFSSM may actually be underestimating the prevalence of food insecurity among resettled refugees in the US. Though research has attempted to establish validity …

Pelagic Fish Diversity And Density On And Off Restored Oyster Reef Habitat, Danielle Mcculloch

Theses and Dissertations

The heterogeneity provided by structured habitats is important in supporting diverse and dense fish communities. The biogenic reefs created by the native Eastern Oyster, Crassostrea virginica, were once the dominant structural habitat in Chesapeake Bay, and have since declined to less than 1% of historic estimates. Conflicting results on the effects of oyster reef restoration on pelagic fish assemblages make further investigation necessary. Incorporating multiple sampling strategies may help elucidate oyster reef habitat influence on fish assemblages. This study used multi-panel gillnets, hydroacoustic technology, and day-night sampling to describe pelagic fish assemblages on and off oyster reef habitat in the …

Survey Of A Neotropical Anuran Assemblage (Pacaya-Samiria Reserve, Peru), Eric Woebbe

Browse all Theses and Dissertations

The Pacaya-Samiria National Reserve of Peru is one of the largest protected areas of the Amazon rainforest, yet it has hosted only a few studies of frogs and toads (anurans). The primary goals of my study are: 1) To conduct an inventory of the local anuran species, 2) to quantify richness among habitats, 3) to compare differences in beta diversity across a river versus a continuous landscape, and 4) to compare difference in body size between nocturnal and diurnal individuals. After eight weeks of daytime and nighttime surveys during the dry season, a total of 601 individuals were identified across …

The Bee Fauna Of The Horse Mountain And Grouse Mountain Region, Humboldt County, California, Carrie Lopez

Cal Poly Humboldt theses and projects

Recent concerns about the ecological well-being of bee communities in California and elsewhere have increased the need for monitoring programs and studies that evaluate the impact of habitat loss and alteration on bee diversity and abundance. Such studies depend critically on the expertise of people trained in taxonomy, but their numbers have declined in recent years. My primary goal was to gain a comprehensive first-hand experience with bee identification by documenting the fauna of a previously unstudied area in the mountains of northwestern California and by writing an identification key, intended for dedicated non-specialists, to the area’s 35 species of …