Land use alters the physical and biological structure of stream ecosystems and potentially alters their capacity to process nitrogen (N), an essential nutrient that has nearly doubled in abundance on the biosphere
during the past century from human activities. In this dissertation, I quantified uptake and transformation of nitrate (NO₃⁻)...
In the fall through spring of 2002/03 and 2003/04, the composition of fish and amphibian communities were examined in intermittent streams in the upper Willamette river basin in western Oregon. I recorded standard aquatic habitat variables and water nutrient concentrations (nitrate and phosphate) and correlated them with fish and amphibian...
This report reviews and summarizes available information on aquatic biological communities in the Willamette Basin through 1995. Specifically, the report describes (1) the distribution, abndance, and trends of three taxonomic groups--algae, macroinvertebrates, and fish--and, to a lesser degree, other selected semi-aquatic taxa (i.e., taxa frequenting but not living wholly in...
Knowledge of how stream habitats change over time in natural and human-influenced ecosystems at large, regional scales is currently limited. A historical stream survey
(1934-1945) was compared to current surveys to assess changes in poo1 habitats in the Columbia River basin. Streams from across the basin, representing a wide range...
Pacific lamprey, Entosphenus tridentatus, have shown recent and rapid declines in abundance. These anadromous fish return to streams where they mature, spawn and die. It has been inferred that Pacific lamprey enter freshwater and reside for ~ 1 year before spawning. This long exposure to the freshwater environment may affect...
As Europeans settled the Willamette Valley in the 1800s, they began to simplify Oregon's largest river contained wholly within state boarders—the Willamette. The river lost miles of channels from dikes, dams, and development. Some channels vanished under concrete. Others became meander scars, or shallow, dry depression in the land where...
This dissertation examines learning driven adaptations in salmon recovery efforts and water resources management in Oregon. The case study utilizes a framework highlighting the connections between human and natural systems. Semi-structured interviews are used to analyze interactions between rural riparian landowners and watershed council staffs living and working in Oregon’s...
The U.S. Bureau of Fisheries (now National Marine Fisheries Service) conducted stream habitat surveys in the Upper Grande Ronde River Basin in 1941. This survey was part of an extensive inventory of stream habitat conditions for anadromous salmonids (Oncorhynchus spp.) throughout the Columbia River Basin. The survey systematically
inventoried 158...
Despite many studies of large wood in streams, few landscape scale studies have been conducted. Large-scale studies can reveal how the history of forest harvest and road building has influenced wood patterns in streams of the Pacific Northwest. This study examined the relationships between wood in streams, timber harvest, and...
