Six headwalls in the central Oregon coast range were selected for study of soil engineering properties and vegetativecharacteristics important for analysis of slope stability. The headwalls were considered representative of those which would be candidates for timber leave areas due to geomorphic and topographic features, including steepness of slope and...
The seasonal duration of snow cover is a primary factor influencing the patterns of vegetation in high subalpine and alpine environments, but little is known concerning the responses of plant reproduction and
seedling recruitment to gradients of snow-release. Vegetation patterns of a high subalpine site in the Oregon High Cascades...
The Three Sisters region of the Oregon High Cascades has developed three compositionally
and petrogenetically distinct silicic (i.e., SiO₂ ≥ 58%) magma systems within the last 600 k.y. These
silicic systems evolved from the same High Cascade mafic magma system and developed in the same
20x30 km area of the...
Seedlings of Gaultheria shallon, Pseudotsuga menziesii, Rhododendron macrophyllum and Tsuga heterophylla were grown together in the greenhouse in soils from three young managed Douglas-fir forests in the Oregon Coast Range. The main objectives were 1 )to evaluate the ability of ericaceous plants and overstory conifers to share compatible mycorrhizal fungi...
Green-tree retention is being implemented on state and
federal lands in Oregon. Silvicultural prescriptions with
tree and snag retention are thought to mimic natural
disturbance patterns in the Pacific Northwest more closely
than traditional silvicultural practices, which reduce
structural complexity. The effects of green-tree retention
on native bird species in...
National Forest management in the Pacific Northwest is shifting
from a focus on commodity production to ecosystem management, in which
the health of the entire forest ecosystem is considered, rather than that
of a few key species. Ecosystem management includes retention of some
live trees following timber harvest (green-tree retention)...
This study assessed how logging-access roads may have contributed to
observed historical increases in peak discharges associated with small and large
logged basins in the western Cascades of Oregon. The study was conducted on
the Lookout Creek (62km²) and the upper Blue River (118km²) basins. Potential
road effects on hydrology...