Because riparian canopy controls most energy inputs to stream
ecosystems, it directly affects the structure of aquatic food webs and the
ecological processes that govern interactions among trophic levels. This
study addresses the interdependence among riparian canopy, benthic
community structure, and the carrying capacity of high desert streams for
salmonid...
This thesis examines factors limiting understory herb presence and flowering in young second-growth Douglas-fir (Pseudotsuga menziesii) forests on the west side of the Cascade Mountains, Oregon, USA. I studied the belowground effects of canopy trees on understory herbs and shrubs in old-growth forests using trenched plots from which tree roots...
Vertically shoot positioned (VSP) training systems are common in Oregon's Willamette Valley, where deep fertile soils and high regional precipitation task growers with curbing vegetative vigor within this system. Management strategies, such as canopy hedging and cluster-zone leaf removal, are used to improve microclimate within the canopy and around the...
The role of disturbance in seed germination and first-year survival of red alder (Alnus rubra) was studied over two growing seasons at four sites representing a climatic gradient within the central Coast Range of Oregon. Disturbance affected red alder seed
germination and seedling establishment by altering the temperature and moisture...
Canopy gap formation is a major factor contributing to maintenance of overstory species diversity and stand structure in forests and may be integral to development of understory shrub and herb layers as well. Acknowledgement of gap formation as a fundamental feature of natural forests has led to consideration of gaps...
To effectively study dynamic processes like forest succession over long time periods one must effectively integrate data collected at many different times, locations and spatial scales. The purpose of this research is to integrate forest inventory data collected by the USDA Forest Service’s Forest Inventory and Analysis (FIA) Program with...
Riparian areas that can be used as reference sites on which to base goals of vegetation restoration have not been documented in the Oregon Coast Range. I examined the composition and distribution of unmanaged riparian overstories in the central Oregon Coast Range along nine streams which have experienced minimal disturbance...
A thermal infrared (TIR) camera is used to remotely sense the foliage temperature in a mountain valley. The foliage temperature is used as a proxy for air temperature and can be used to study and map the dynamics of the nocturnal, weak-wind boundary layer in this valley. All radiative flux...
Potato ground cover and spectral data were measured
in the Columbia Basin during the 1990 growing season.
Three spectral were correlated with ground cover;
normalized difference, near infrared-red ratio, and the
first derivative of the spectral curve at 750 nm. All
models were statistically significant at the 99% level.
Normalized...
The accurate simulation of snowpack deposition and ablation beneath forested areas is confounded by the fact that the vegetation canopy strongly affects the snow surface energy balance. The canopy alters the radiation balance of the snowcover, and reduces the wind speed at the snow surface. Data collected as part of...
