Large organic debris has important biological and physical
roles within the stream ecosystem. In order to determine the source
area of large organic debris in streams, thirty-nine streams in the
Cascade and Coast Ranges of Oregon and Washington were sampled. The
distance from point-of-origin to channel was measured for thirty...
The structure of a mature Douglas-fir (Pseudotsuga menziesii)
forest in a watershed in the western Cascades of Oregon was examined.
Two age classes were detected in the stand, the oldest originating
about 1855 after an extensive fire and the younger following a second
fire about 1895 Although the trees in...
Information concerning the factors controlling seedling establishment on tephra deposits (airfall volcanic ejecta) is limited. The establishment and growth of six coniferous species, Abies amabills (Dougl.) Forbes (Pacific silver fir), A. procera Rehd. (noble fir), Pinus monticola Dougl. (western white pine), P. Contorta Dougl. (lodgepole pine), Pseudotsuga menziesii (Mirb.) Franco...
Phytophthora root rot decreases availability and quality of rhododendrons produced in the USA. Symptoms of Phytophthora root rot include root necrosis, leaf chlorosis, stunting, and permanent wilt. The purpose of this thesis was to better understand the impact of root damage, soil moisture, nitrogen fertilizer application, and pathogen species on...
