Life Sciences Commons^™

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 …