Determination of the source and fate of natural (higher plant lipids, marine
lipids, etc.) and anthropogenically (e.g., petroleum, coal emissions) derived
hydrocarbons and oxygenated compounds in the environment was accomplished
using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS)
to characterize or identify molecular biomarkers to be utilized as tracers....
Ecosystems are highly heterogeneous systems subjected to important levels of environmental variability; however, it is common in terrestrial biogeochemical models to assume homogeneous properties of the elements of the system or constant environmental conditions. For some processes, heterogeneity in these models is treated very simplistically, but there is not much...
This thesis investigates the behavior of major inorganic nutrients (P, N, Si), trace metals (Mn, Fe), and alkaline-earth metals (Ba) within Tillamook Bay over seasonal cycles and under a range of river discharge conditions from October 1997 through December 1999. Located in the Pacific Northwest region, Tillamook Bay is an...
Surface transient storage (STS) and hyporheic transient storage (HTS) have functional significance in stream ecology and hydrology. Both provide refugia for aquatic communities and their longer mean residence times (compared to the main flow) increase the potential for biogeochemical reactions that can improve water quality. As STS and HTS have...
After three decades of active research coupling hydrology and stream ecology, the connection among solute transport, metabolism and processing is still unresolved. These knowledge gaps obscure the functioning of stream ecosystems and how those ecosystems interact with other landscape processes. We must resolve these challenges to wisely manage water resources,...
The kinetics of physical and chemical processes controlling the precipitation of iron oxide minerals in unsaturated media were investigated in this study. The characteristic morphology, mineralogy, and chemistry of iron oxides were also explored. Laboratory column experiments using fine and coarse grades of silica sand were conducted to compare the...
The objectives for year have been the gathering of existing information, initiation of monitoring water quality, evaluation of analytical methods and procedures for measuring nutrient regeneration in the sediment-water interface, and the study of growth-environment correlations in Findley Lake, Chester Morse Reservoir, and Lakes Sammamish and Washington. Progress was made...
Forest harvest persists as one of the most globally important industries, and crucially provides raw wood products for both building and fuel materials. Mechanistically complex abiotic and biotic processes curb ecosystem recovery following timber harvest and it is of great importance to understand the effects of this practice on biogeochemical...
Background information is presented that provides historical perspectives on the field of mycology in the Pacific Northwest and its role in forest management. The series of events and decisions that have led to previous studies (or lack of studies) in the field also dictate the directions of current research. Culture,...