This analysis explores potential changes in the behavior of Oregon's Supplemental Nutrition Assistance Program (SNAP) participants after the 2008 recession. I examine this using individual-level administrative data from the State of Oregon in a linear probability model and a duration model. After controlling for a standard set of factors known...
Three studies on Douglas-fir beetle (DFB), Dendroctonuspseudotsuae, were conducted to investigate its basic and applied biology. Studies included investigations into the spatial relationship of DFB infestations over multiple years and multiple landscapes, relationships between DFB brood adult lipid levels and position of development along the length of tree boles, and...
Many marine fish populations are severely declining due to over-fishing, loss of both juvenile and adult habitats, and accelerating environmental degradation. Fisheries management and the implementation of marine protected areas (MPAs) and other conservation tools are currently hindered by large gaps in knowledge about larval dispersal and its subsequent effects...
The purpose of this study is to examine how rhetoric functions in the
Alternative Birth Movement (ABM). In particular, communication published by
movement leaders will be examined to discover how rhetoric propels the movement from
one stage to the next as well as how rhetoric facilitates the goals of the...
This thesis examines the Schultz Fire as a case study to explain the complex history of fire suppression management in America’s forests, and to gain further understanding of how management practices have affected the increase in fire severity levels and how forests respond to such a disturbance. The thesis objectives...
The rapid accumulation of polyethylene terephthalate (PET) plastic waste caused by disposable plastic water bottle use is a worldwide problem that will continue to affect our environment, economy and society unless new methods of reduction and degradation are explored. The large amounts of energy and resources that are required during...
Changes in climate caused by increased concentrations of carbon dioxide (CO₂) in the Earth’s atmosphere have led land and ocean surface temperatures to increase by 0.85°C and sea level to increase by 19 cm relative to preindustrial times. Global climate change will lead to further alterations in mean temperature and...
Predators are fundamentally important for regulating and driving prey population dynamics as well as structuring ecological communities. Over-exploitation of marine resources has caused dramatic depletions of predatory fish species and shifts in marine community composition, with attendant declines in productivity and diversity of marine ecosystems. Despite the important ramifications of...
Invasive species are a growing global economic and ecological problem. Invasive Indo-Pacific lionfish (Pterois spp.) are known to have extreme negative effects on coral-reef communities in the Bahamas, so understating their distribution within and among reefs, what limits their local movements, and the effects they have on native prey species...
Although only a minority of introduced species become established and have noticeable consequences in their new communities, some can displace native species, alter food webs, and cause local extinctions. Studying these invasive species can provide new insights into basic ecological questions as well as inform management strategies. Pacific lionfish (Pterois...
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Mark A. Hixon
Although only a minority of introduced species become established and