Non-target effects are one of the greatest potential risks of weed biological control programs, and understanding non-target effects of biological control at the population level is crucial for predicting when they will occur and altering the perception of biological control as a whole. In this thesis, we assessed the ecological...
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Peter B. McEvoy
Non-target effects are one of the greatest potential risks of weed biological
In the first part of this study we monitored the development of biological control
of purple loosestrife Lythrum salicaria over a six-year period at Morgan Lake in western
Oregon. In 1992, two beetles, Galerucella pusilla and G. calmariensis (Coleoptera:
Chrysomelidae), were released to control the wetland weed at this test...
Contemporary environmental change encompasses massive biodiversity loss and
increasing numbers of emerging diseases worldwide. As part of a global biodiversity
crisis, amphibians are disappearing at unprecedented rates. Batrachochytrium
dendrobatidis is an emerging infectious pathogen prominently associated with many
declines. Chapter 1 reviews the past decade of research on this system...
The "old-growth controversy" in the Pacific Northwest recognized thinning as the
primary silvicultural practice for land managers to produce wildlife habitat while
continuing to produce timber. For the foreseeable future, forest stands will be harvested to
produce forest gaps and a patchwork of trees of different ages. In order to...
Two of the most powerful ways in which humans have altered ecosystems are by increasing productivity and changing the densities of important consumers. The bottom-up effects of productivity and the top-down effects of consumers have been identified as primary determinants of biological diversity, though the links between them remain unclear....
Wildfire is an annual threat for many rural communities in the Pacific Northwest region of the United States. In some severe events, evacuation is one potential course of action to gain safety from an advancing wildfire. Since most evacuations occur in a personal vehicle along the surrounding road network, the...
Careful analysis and thoughtful synthesis will be necessary for expanding the envelope of
ecological understanding. This work is my attempt at communicating both of these, in relation
to three questions about our understanding of the structure and dynamics of biological diversity.
These questions focus on a) advancing our understanding of...
The relationship between nutrients and community structure is poorly understood in open-coast habitats. I created a system of artificial tidepools, of identical age and physical dimensions, at two sites that differed in wave exposure, and manipulated nutrient levels and the abundance of herbivores. Using these unique field mesocosms, I explored...
A comprehensive tribal-level classification for the world's subfamilies of Hesperiidae, the skipper butterflies, is proposed for the first time. Phylogenetic relationships between tribes and subfamilies are inferred using DNA sequence data from three gene regions: 943 bp of cytochrome oxidase subunit I (COI) (in the mitochondrial genome), 739 bp of...
Peroxiredoxins (Prxs) are dominant peroxide-reducing enzymes with two important roles: they protect all organisms from oxidative damage induced by peroxides, and in eukaryotes, they participate in hydrogen peroxide signaling pathways. This dissertation presents studies aimed at the biophysical characterization of select Prxs and a Prx reductase to elucidate their structure-function...