Xylem conducting tissue or sapwood is an important storage organ
for water, carbohydrates, and nutrients, and this storage helps trees
accommodate environmental change. However, the living ray parenchyma
cells in sapwood, which store the carbohydrates and nutrients,
require energy for maintenance. I examined how sapwood maintenance
costs vary among species,...
This project, to propose an implementation strategy for standard monitoring
protocols, builds on my Pacific Northwest National Laboratory Fellowship to support a
study entitled Evaluating Cumulative Ecosystem Response to Restoration Projects in the
Columbia River Estuary (Diefenderfer et al. 2005). The major objective of the study was
to develop a...
An infiltration capacity and surface erodibility study was conducted six years after forest harvesting in the Oregon Cascades. A portable rainfall simulator was utilized to obtain field measurements on the Coyote Creek and Hi-15 Watersheds during summer and fall, 1977. Seasonal variations were found to occur in infiltration
capacities and...
Light Detection and Ranging (LiDAR) remote sensing has demonstrated potential in measuring forest biomass. We assessed the ability of LiDAR to accurately estimate forest total above ground biomass (TAGB) on an individual stem basis in a conifer forest in the US Pacific Northwest region using three different computer software programs...
Sampling patterns and sampling errors from various scatterometer datasets are examined. Four single and two tandem scatterometer mission scenarios are considered. The single scatterometer missions are ERS (with a single, narrow swath), NSCAT and ASCAT (dual swaths), and QuikSCAT (a single, broad swath obtained from the SeaWinds instrument). The two...
A critical seasonal event for anadromous Chinook salmon (Oncorhynchus tshawytscha) is the time at which adults migrate from the ocean to breed in freshwater. We investigated whether allelic variation at the circadian rhythm genes, OtsClock1a and OtsClock1b, underlies genetic control of migration timing among 42 populations in North America. We...