Treesearch

A natural decline in the population of yellow-cedar (Chamaecyparis nootkatensis) is occurring in pristine southeast Alaska forests and may be the most significant forest decline in the western United States. The frequency of landslides in cedar decline areas is three times larger than in areas of healthy forest. Three regions are investigated in order to determine the influence of yellowcedar decline on root strength, soil saturation, and consequently, slope stability. Nearly complete deterioration is observed in roots up to 25 mm thick on cedar trees that have been dead for approximately...

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.

Mixed-conifer stands of grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco), and ponderosa pine (Pinus ponderosa Dougl. ex Laws.) were fertilized with nitrogen and combination treatments of nitrogen, phosphorus, potassium, and sulfur to test their effects on trees and associated insects during an outbreak of the western spruce budworm (Choristoneura occidentalis Freeman). None of the treatments significantly influenced the impact of defoliation on foliage and shoot growth, radial increment, or tree mortality. The only...

Within-stand variation in understory species composition and biomass was studied in 16 even-aged stands of mixed red alder-Sitka spruce-western hemlcock (Alnus rubra-Picea sitchensis-Tsuga heterophylla) forest. The sites were upland sites, and the stands were 28-39 years old. We compared understory within three categories of microsite types: Red alder-dominated, conifer-dominated, and mixed alder-conifer. Biomass of forbs and ferns differed significantly (p < 0.05) between microsite types, being greatest in alder microsites, least in conifer microsites, and intermediate in mixed alder...

In the 1980s resource managers were increasingly concerned about effects of timber harvest on ungulates in National Forests. Land and resource management plans incorporated restrictions on timber harvest to maintain cover for Rocky Mountain elk (Cervus elaphus nelsoni V. Bailey) and mule deer (Odocoileus hemionus hemionus Rafinesque), and habitat models were used to predict effectiveness of various habitat components for these ungulates. Many of the assumptions on which these models were based were untested, however. The Starkey Project, in northeastern Oregon, was begun to address some of...

Tree seedling establishment and growth were studied in experimental canopy gaps to assess the effect of heterogeneity of regeneration microsites within and among gaps in mature conifer forests. Seedlings were studied for two years in closed-canopy areas and in recently created gaps ranging in size from 40 to 2000 m2 in four stands of mature (90-140 yr) and old-growth (>400 yr) Douglas-fir forest in the western Cascade Range of central Oregon and southern Washington. USA. We examined the relative importance of substrate type, shade from logs and shade cloth, density of understory vegetation,...

Fire frequcncy, intensity, and size can influence the nature of forest development, with potentially profound effects on ecosystem processes and the abundance of native species. The effect of an intense wildfire and subsequent severe fires within a short period (reburns) on forest establishment, composition, and structure was examined in the 16,000 ha Siouxon Creek watershed in the western Cascades of southern Washington. Evidence of large intense fires and small patchy flres was found in the watershed, with 4 fires occurring since 1900. Tree establishment was rapid and abundant throughout...

Mark-release-recapture experiments were performed with spruce beetles (Dendroctonus rufipennis (Kirby)) and Ips engraver beetles (Ips perturbatus (Eichhoff)) to determine distance and direction of dispersal. The recapture rate of beetles marked with fluorescent powder was extremely low. Most I. perturbatus beetles dispersed up to 30 m from their overwintering sites compared to most D. rufipennis, which dispersed from 90 to 300 m. Ips perturbatus beetles were caught up to 90 m and D. rufipennis up to 600 m from the point of release.

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. View an updated online version of this publication with downloadable excel files athttps://www.fs.usda.gov/pnw/ppet/.