Intragravel organic loading and intragravel dissolved oxygen were studied to determine the relationship between timber harvesting adjacent to first-, second-, and third-order streams and intragravel water quality. Twenty watersheds in the central Coast Range of western Oregon were studied of which five were undisturbed, nine were partially harvested, and six...
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 use of mechanized harvest equipment has been
increasing as an economical method to harvest small diameter
timber. While the use of this equipment is increasing,
little is known about associated soil compaction. In
particular, little information exists on soil compaction
caused by feller--bunchers.
This study measured soil compaction caused...
Mass soil movements of four types; debris avalanche, debris torrent, debris slide and bank slough, were field inventoried in the Oregon Coast Range. A total of 104 mass movements were located in 21 undisturbed watersheds and 13 clearcuts harvested in the last six years. Failures associated with roads and landings...
Summer low flow characteristics of six forest streams in Northeast Oregon were examined using long term streamflow records. Time series and trend analysis revealed highly significant (alpha=O.O1) increasing trends in summer low flow over the period of record on four of the selected streams, and significant (alpha=O.05) year-to-year
dependence on...
Tillage of forest soils compacted by ground-based logging systems is a practice that is becoming widely accepted in the Pacific Northwest. However, past research has failed to adequately define the conditions and specifications that particular tillage operations should meet in order to produce the maximum growth response from planted seedlings....
This study evaluated the recovery of compacted soils on logging
skid trails in clearcuts of the western Cascade Mountains of Oregon.
Soil types included clay, clay loam, silt loam, loam, sandy loam
and loamy sands. Sites ranged in age from five to 38 years since
harvest and 370 to llOOm...
This study investigated the development of riparian zone vegetation at varying stand ages from one to 29 years following clearcut timber harvesting in western Oregon. Vegetation was classified into three layers for observation including the ground (less than 13 cm), the understory (less than 2.5 m), and the overstory (greater...
The growth of Alnus acuminata (HBK) 0. Ktze, Cupressus
lusitanica Mill., Gmelina arborea Roxb, Pinus caribaea var. hondurensis
Barr. & Golf., and Tectona grandis L. in Costa Rica and
twenty seven soil and climatic factors were analyzed to determine
the relationship between major environmental factors and growth
rates of these...
This study focused on extensive soil mass movement occurrence
in the Willamette National Forest of western Oregon and on intensive
measurements of some physical and biological changes in
streams following debris torrents. Debris torrents are a rapid
movement of water-charged debris confined to steep headwater channels.
The frequency (events/ha/yr) of...
