Treesearch

Data from six western States provided 1,251 life tables representing western spruce budworm, Chodstoneura occidentalis Freeman. These data provided projection capabilities for defoliation and successive budworm densities, as well as a basis for comparing survival rates among the three principal North American needle-eating budworms (western and eastern spruce budworms, and the jack pine budworm). Several modifications are suggested in current methods for managing budworm-susceptible forests, and suggestions are provided for further studies on the budworm life systems.

Provisional seed zones and breeding zones were developed for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in the Siskiyou National Forest in southwestern Oregon. Zones were based on maps of genetic variation patterns obtained by evaluating genotypes of trees from 260 locations in the region. Genotypes controlling growth vigor and growth rhythm were assessed in a common garden. Within the Forest, three breeding blocks were recommended, with different numbers of elevational bands in each block: from 0 to 610 meters, from 611 to 838 meters, and then a series of bands 152 meters wide at...

The fire-adapted forests of the Blue Mountains are suffering from a forest health problem of catastrophic proportions. Contributing to the decline of forest health are such factors as the extensive harvesting of the western larch and ponderosa pine overstory during the 1900s, attempted exclusion of fire from a fire-dependent ecosystem, and the continuing drought. The composition of the forest at lower elevations has shifted from historically open-grown stands primarily of ponderosa pine and western larch to stands with dense understories of Douglas-fir and grand fir. Epidemic levels of...

Log exports have been restricted in British Columbia for over 100 years. The intent of the restriction is to use the timber in British Columbia to encourage development of forest industry, employment, and well-being in the Province. Logs have been exempted from the within-Province manufacturing rule at various times, in varying amounts, for different reasons, and by changing procedures. Although policy clearly restricts log exports, the effects are not simple. The timber industry benefits from both financial returns due to exporting and a restricted log market, while policy changes and...

The commercial harvest of edible forest fungi has mushroomed into a multimillion dollar industry with several thousand tons harvested annually. The development of this special forest product industry has raised considerable controversy about how this resource should be managed, especially on public lands. Concerns center around destruction of forest habitat by repeated entry and harvest, gradual loss of the mushroom resource by potential overharvest, conflict between recreational users and commercial harvesters, and regulation and monitoring of future harvests. A key to wisely managing the...

Provides current information on lumber and plywood production and prices; employment in the forest industries; international trade in logs, lumber, and plywood; volume and average prices of stumpage sold by public agencies; and other related items.

Provides current information on lumber and plywood production and prices; employment in the forest industries; international trade in logs, lumber, and plywood; volume and average prices of stumpage sold by public agencies; and other related items.

Provides current information on lumber and plywood production and prices; employment in the forest industries; international trade in logs, lumber, and plywood; volume and average prices of stumpage sold by public agencies; and other related items.

Logarithmic regression equations were developed to predict component biomass and leaf area for an 18-yr-old genetic test of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) based on stem diameter or cross-sectional sapwood area. Equations did not differ among open-pollinated families in slope, but intercepts assuming equal slopes did differ for equations predicting leaf, branch, or bark biomass, or leaf area. These results may be explained by family differences in partitioning between stemwood and bark and between stem and crown. Predictions of biomass and leaf area based...

We studied prey populations and the use and composition of home ranges of 47 Northern Spotted Owls (Strix occidentalis caurina) over 12 mo in five landscapes in two forest types in southwestern Oregon. We measured 1-yr home ranges of 23 owl pairs, 2-yr home ranges of 13 pairs, and 3-yr home ranges of 3 pairs. The landscapes differed in the degree to which old forest had been fragmented by wildfire and logging. Prey populations were measured at 47 sites in southwestern Oregon. Further data on prey populations were gathered on 14 sites on the Olympic Peninsula in northern Washington. where...