Life Sciences Commons^™

Assessing Threats To Plant Populations: Linking Pollinator Differences To Patterns Of Plant Fitness And Population Genetics, Rieka Yu

Dissertations

Land use change is a major driver of biodiversity loss and consequently has led to the loss of genetic diversity in many plant populations due to declines in population sizes and an increase in spatial isolation. However, not all plant populations respond similarly to land-use change, suggesting there are additional mechanisms mediating plant population genetic patterns. Here, I examine the role of pollinators as this mediating factor. In Chapter 1 I conducted a meta-analysis to investigate how different types of pollinators drive changes in gene flow for plant populations in disturbed habitats, finding that different types of pollinators mediate different …

Predicting Mountain Lion Resource Selection And Abundance In North America, William Connor O'Malley

Graduate Student Theses, Dissertations, & Professional Papers

The relationship between habitat quality and density is well documented in lower trophic levels but to what extent it can be extended to higher trophic levels is unknown. I tested the relationship between habitat quality, home-range size and density using a wide-ranging, well-studied, top carnivore, the mountain lion (Puma concolor). First, I created a second-order resource selection function (RSF) for mountain lions in their current North American range using GPS collar data from 476 individuals in 20 study sites and remotely-sensed landscape data. I used the RSF and home range estimates derived from collared animals to quantify mountain …

Animal Husbandry In The 21st Century: Application Of Ecological Theory And Precision Technology To Inform Understanding Of Modern Grazing Systems, Ira Lloyd Parsons

Theses and Dissertations

Ruminant animals comprise the greatest proportion of herbivores around the world, provide essential ecosystem services and human consumable protein by consuming grass and human inedible dietary fiber. Herbivory pressure alters plant communities and species diversity, effectively making grazing animals ecosystem engineers in dynamic ecosystems. Development of advanced computer processing power coupled with biometric and ecosystem sensors may be employed in the internet of things framework to create an integrated information system designed to inform understanding of grazing system function and animal energy balance. Towards this end, I utilized Bos indicus / Bos taurus crossbred steers (n = 20) across two …

Combining Historic Records And Multi-Criteria Habitat Suitability Analysis For The Potential Reintroduction Of Lake Sturgeon (Acipenser Fulvescens Rafinesque) Into Tributaries Of Lake Erie, Kylie P. Wirebach, Christopher Pennuto, Dimitry Gorsky

Biology Theses

Predicting the location and quality of habitat for imperiled species is an increasingly important application of modeling technology. The Lake Sturgeon (Acipenser fulvescens) is a widely-extirpated fish of the Laurentian Great Lakes whose recovery is dependent on the availability and connectivity of suitable stream habitat today. This is especially true in Lake Erie, where the largest Lake Sturgeon fishery was once found. I predicted that modern habitat suitability would be dependent on land use legacies from the past 200 years, with western Lake Erie tributaries having less suitable habitat compared to the eastern Lake Erie tributaries. I developed a multi-criteria …

Mortality Risk Associated With Urban Land Use For Adult Eastern Diamondback Rattlesnakes (Crotalus Adamanteus), Mya Wiles

Theses, Dissertations and Capstones

Snakes have been a traditionally under-represented organism in urban ecology, but they face similar, if not greater challenges in the face of growing urban sprawl. Eastern diamondback rattlesnakes (Crotalus adamanteus, EDBs) are under consideration for listing under the Endangered Species Act due to population declines resulting from historical human persecution and habitat loss. This study used radio-telemetry data from a long-term monitoring project of adult EDBs on a developed sea island in South Carolina, USA. I reclassified a National Land Cover Dataset to reflect relative mortality risk for snakes attempting to move through the landscape. High-risk cover types …

Exploring Linkages Between Landscape Patterns And Freshwater And Estuarine Bivalves In The Coast Range Of Oregon, Kaegan Michael Scully-Engelmeyer

Dissertations and Theses

Spatial configurations of landscape variables (biotic, abiotic, and socio-ecological) affect and are affected by ecological processes and species in watersheds. This dissertation explores relationships among landscape patterns, ecosystem processes and bivalve species dynamics in coastal watersheds in Oregon, USA. I approached this broad topic through two primary avenues of research: investigating cross-ecosystem threats from pesticide use in forestland management to downstream aquatic environments, and the landscape ecology of an at-risk freshwater mussel species.

Terrestrial land use activities present cross-ecosystem threats to riverine and marine species and processes. Specifically, pesticide runoff can disrupt hormonal, reproductive, and developmental processes in aquatic organisms, …

Distribution And Ecological Effects Of Azteca Chartifex/Trigona In The Barro Colorado Nature Monument., Rachel Leann Wells

Electronic Theses and Dissertations

This dissertation explores the behavior and ecology of a conspicuous and behaviorally dominant ant species in the tropical rainforest of Panama. Competition with aggressive species is an important factor that shapes local community structure. Eavesdropping on the chemical communication systems of such behaviorally dominant species can help heterospecific species to avoid negative interactions. I review the chemical communication system and known ecological effects of the Neotropical canopy ant, Azteca chartifex/trigona (Chapter 1). There are over 40 known compounds produced by Azteca workers, yet how these compounds impact heterospecific species is unclear in many circumstances. I assessed if heterospecific …

Pollinator Ecology In Agroecosystems Of Eastern South Dakota, Isabela Beatriz Vilella-Arnizaut

Electronic Theses and Dissertations

Community structure contributes to ecosystem persistence and stability. To understand the mechanisms underlying pollination and community stability of natural areas in a human influenced landscape, a better understanding of the interaction patterns between plants and pollinators in disturbed landscapes is needed. Furthermore, understanding the potential conservation value in green spaces such as botanical gardens could assist in preserving and bolstering plant-pollinator interactions. Our study takes place in the Northern Great Plains which still retains extensive tracts of remnant temperate grassland habitat within a matrix of varying land-uses. First, we used a network-based approach to quantify how temperate grassland attributes and …

Searching For Gold: Using A Novel Land Cover Classification To Identify Multiscale Drivers Of Site Occupancy By A Flagship Species For Early-Successional Habitat Conservation, Baron Lin

Theses and Dissertations

Understanding habitat selection at multiple scales is an important step in guiding conservation programs and reversing species declines. This, however, is difficult for species that occupy early-successional habitats (ESH) due to a lack of accurate representation of shrub cover in publicly available land cover data. The Golden-winged Warbler (Vermivora chrysoptera; GWWA) is a threatened species of conservation concern and a flagship for ESH conservation. We used a novel, LIDAR-derived land cover classification that accurately identifies shrubs at a fine resolution (1m) to investigate how habitat composition and configuration influence GWWA site occupancy. We aggregated this same land cover …

The Influence Of Land Use On The Pollen Diet Of Honey Bee (Apis Mellifera) Colonies In Ellis County, Kansas, Ryan Engel

Master's Theses

Pollinators are integral to plant ecology as well as to worldwide food availability and security. Understanding how human-driven land use change impacts the nutrition of managed honey bees is important in pollinator conservation efforts and can contribute towards combating recent pollinator declines. The objective of this study was to determine sources of forage for honey bees across different land use types in Ellis County, Kansas, through pollen analysis and taxonomic identification. Replicate study colonies were placed in three separate land use types: Urban, Cropland, or Native/Semi-native prairie. Pollen was sampled every 7 to 14 days throughout a growing season (April …

Effects Of Disturbance On Jack Pine- (Pinus Banksiana Lamb.) Dominated Ecosystems In Northern Lower Michigan: Forest Management, Wildfires, And Climate Change, Madelyn Tucker

Wayne State University Dissertations

Jack pine-dominated forests in northern Lower Michigan were historically characterized by a frequent, severe fire regime that produced a patchwork of dense stands interspersed with open barrens. This structure also provided breeding habitat for Kirtland’s warblers, a migratory songbird. Fire suppression management caused forests to become older and reduced Kirtland’s warbler habitat, resulting in severe population losses. Kirtland’s warblers were designated as endangered, and subsequent habitat management has produced homogeneous forests that lack historical structural and compositional diversity. Moreover, future climate may increasingly complicate forest and fire management moving forward. In a landscape defined by disturbance, novel disturbances or changes …

Landscape Ecology Of Birds On Mount Leconte, Great Smoky Mountains National Park, Andreas P. Damalas

Biological Sciences Theses & Dissertations

Landbirds form a significant component of wildlife resources in the Great Smoky Mountains National Park. The present study explored how forest structure and composition of deciduous-coniferous ecotones influenced diversity, richness, and relative abundance of bird species and how bird species responded to the spruce-fir community.

Using a form of the variable-circular plot method, I conducted audio-visual censuses of diurnal birds on Mount LeConte. I established 212 geo-referenced census points on six trails, which were used as gradient-oriented transects (gradsects). I measured habitat characteristics at the same census points. I used forest community types for each point on gradsects to delineate …