Treesearch

At least 99 species, representing 14 families of Trichoptera, are recorded from the H.J. Andrews Experimental Forest, near Blue River, Oregon. The collecting sites include a wide diversity of environmental conditions in a 6000-hectare watershed of the western Cascade Range (from 400 to 1 630 meters in altitude and from 1st- to 7th-order streams).

Environmental factors were related to forest regeneration on clearcut and partially cut areas managed by the Bureau of Land Management in the Hungry-Pickett area northwest of Grants Pass, Oregon. The multiple regression equations developed for this study can be used to compare the relative difficulty of regenerating forested sites within the study area. The equations show that difficulty of regenerating clearcuttings increases with increasing solar radiation, temperature, rock cover, and depth of the soil A horizon. Difficulty of regenerating partial cuts increases with surface gravel...

The 15-year growth response from a levels-of-growing-stock study in an even-aged western larch (Larix occidentalis Nutt.) stand in northeastern Oregon, first thinned at age 33, showed that trees growing at lower stand densities grew more rapidly in diameter but did not grow faster in height than trees in high density plots. Both basal area and total cubic volume increment increased as stand density increased. Despite the large reduction in volume increment at the lower densities, however, most of the wood is concentrated on fewer, faster growing trees that can reach usable size sooner.

This report summarizes a 1977 inventory of timber resources in 17 Oregon counties east of the crest of the Cascade Range. Detailed data on forest area, timber volume, growth, mortality, and harvest are presented.

Agricultural yield strategy simply aims to increase number of grain bearing stalks per acre. Forestry strategies look to thinning, fertilizer, and genetics, each to provide gains. The agricultural strategies applied to Douglas-fir appear to be impractical for long rotations. Concern is expressed for commitments to perpetual inputs of materials and energy to keep a yield above the land’s carrying capacity. Adapted natural populations are the major resource in keeping a yield improvement strategy trouble-free.

Distribution of anadromous salmonids and coniferous forest coincides along much of the Pacific slope; consequently, the habitat of anadromous' fish is subject to a wide variety of silvicultural treatments required to establish and nurture young forests. Silvicultural treatments discussed in this report include cutting prescriptions, broadcast burning, mechanical site preparation, planting, and competition reduction. Timber harvest, and use of pesticides and fertilizers are discussed in other papers in this series. Broadcast burning and machine scarification and piling can increase sedimenta...

A 29-year record of seedfall in thinned and unthinned portions of a Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand, spanning ages 39 through 68, reveals annual seed production from no seeds to about 3 million per hectare. For the nine largest crops, annual seedfall in the best seed-producing thinning treatment included at least 100 000 filled seed per hectare. The first of these nine crops was in 1950; the other eight occurred at 1- to 4-year intervals beginning with 1959. For the nine largest crops, the proportion of seeds filled averaged 45%o and ranged from 30 to 54%. Typically...

Current techniques for rehabilitating and enhancing habitat to increase natural production of anadromous salmonids in the Pacific Northwest and Alaska are described. Methods to enhance spawning, rearing, and riparian habitat, and to improve access are reviewed. The information was compiled from published literature, unpublished reports by State and Federal agencies, and personal communications, including visits with project personnel. Protection of habitat is the best investment for sustaining anadromous salmonid production, but rehabilitation and enhancement projects in the Pacific...

Relationships of mule deer behavior and physiology to management of shrub steppe plant communities in the Great Basin of southeastern Oregon are presented for application in land-use planning and habitat management. Communities are considered as they are used by mule deer for thermal cover, hiding cover, forage, fawning, and fawn rearing.

Changes in depth to permafrost and soil temperature were investigated for 4 years after treatment of the forest floor on small plots by fire and mechanical removal of half the forest floor layer and the entire layer. The only treatments to show a consistent, statistically significant effect were the mechanical removals. Fire treatments usually did not have a statistically significant effect on depth to permafrost and soil temperature in summer; fire consumed only small amounts of the forest floor because of wet conditions at the time of burning. Treated plots showed an almost constant drop...