Current riparian management objectives in the Pacific Northwest promote both retention of existing conifers and conversion of hardwood-dominated areas to conifers. Although understanding of relationships between riparian vegetation and salmonid prey availability is growing, temporal variation in these relationships is poorly understood. Seasonal fluxes in availability of aquatic and terrestrial...
Invasion by nonnative brook trout (Salvelinus fontinalis) often results in replacement of bull trout (Salvelinus confluentus) in western North America, but the causal mechanisms are not well understood. Removal of brook trout from 1992 to 2000 from Sun Creek in southern Oregon, provided an opportunity to investigate the changes in...
Three methods--radial compression strength, color indicators of decay and micro-toughness, an examination of tracheid fracture patterns, were evaluated for detection of early decay and for application to field use. Three-eighth-inch diameter plugs 3/4-inch long, cut from the sapwood and heartwood of a Douglas-fir pole free of decay, were decayed by...
Allowable stresses in compression perpendicular to the grain (C-perp) have been too conservative for most structural uses. This study develops stress data for deformations beyond the proportional limit (PL), up to 0.1 inch for hem-fir. Fifteen boards from four western states were cut into small specimens representing three ring angle...
A new carbohydrate-phenol based resorcinol resin
(CPR resin) was synthesized by end capping a known
carbohydrate-phenol based resole with resorcinol under
basic reaction conditions. Synthetic parameters, such as
duration of cook, pH, and the amount of resorcinol and
formaldehyde were varied to produce resins with molecular
weights (Mw) ranging from...
This study was conducted to determine how the size and orientation of large
wood placed in streams in combination with peak flows, substrate and channel gradient
affect pool volume, surface area and maximum depth in two coastal Oregon streams.
Eighteen Douglas-fir (Pseudotsuga menziesii) logs were placed in each of two...