Shrub-steppe ecosystems of western North America provide habitat for many wildlife species, are important components of public and private rangelands, and offer recreational opportunities for millions of people. They are some of the most vulnerable ecosystems in the United States and have been altered by human activities such as livestock...
Remote sensing techniques have long been useful in quantifying changes in ecosystems and the field of remote sensing is constantly evolving to better assess and describe changes, both spatially and temporally. In this thesis I explored the novel use of two remote sensing methods to quantify ecosystems; repeat photograph to...
In many regions of the world, a significant portion of the surface water originates in mountain headwaters where the timing and magnitude of streamflow is largely dictated by the seasonal storage of precipitation as snowpack and long-term storage as glaciers. Accumulation, persistence, and melt of snow and ice are functions...
Duplex stainless steels (DSS) are an attractive potential material in nuclear power generation systems due to an excellent combination of corrosion resistance, strength, toughness, and affordability. Thermal embrittlement caused by phase instability in the temperature range of ~300-550°C severely limits the service temperature of DSS. The rate of embrittlement varies...
The current rate of global biodiversity loss and extinctions is unparalleled and a major concern. Freshwater organisms are facing particularly rapid rates of biodiversity loss. Amphibians, which require an aquatic environment for part of their life cycle, are one of the most vulnerable vertebrate groups. Amphibians are experiencing population declines,...
This study explored the relationship of mature ponderosa pine (Pinus ponderosa Dougl. ex Laws) tree vigor and competitive zone density following thinning and fuel reduction treatments. Competitive zone density (CZD) was defined as the total tree basal area (m²/ha) surrounding a given ponderosa pine tree within a 10m fixed radius...
Policy regarding the management of public forests has undergone a drastic shift over the past couple of decades due to the loss old-growth forests in the Pacific Northwest (PNW) of the United States. For much of the 20th century, forest management on public lands emphasized timber production through the use...
Forest soils contain a substantial portion of global terrestrial carbon stores. Forest management can influence the soil carbon pool and how soil organic matter functions. The long-term productivity of forests is an ongoing goal where land managers utilize biomass and timber. A site-specific understanding of intensively managed forests can ensure...
Roughstalk bluegrass (Poa trivialis L.) (RB) is a weed species that increased very quickly in grass seed production fields of the Willamette Valley. The invasion of RB in grass seed crops often occurs in waterlogged soils. In waterlogged areas, RB exhibited better competitiveness and had greater population densities than other...
Coastal marsh vegetation is an important component in maintaining marsh stability that is threatened by changes in sedimentation, sea level rise, natural and anthropogenic disturbances, and competition from invasive species. Vegetation has been demonstrated to reduce wave energy, increase sedimentation, and decrease erosion in tidal environments under a range of...