Treesearch

The cooperative levels-of-growing-stock (LOGS) study in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) was begun to study the relations between growing stock, growth, cumulative wood production, and tree size in repeatedly thinned stands. This report summarizes results from the Hoskins installation through age 55. Growing stock has been allowed to accumulate for 19 years since the last treatment thinning was applied in this high site class II natural stand. Volume and diameter growth were strongly related to growing stock. Basal area growth-growing stock relations were considerably...

This report examines the differences in wood characteristics found in coastal Pacific Northwest Douglas-fir (Pseudotsuga mensziesii (Mirb.) Franco) trees harvested at the age of 70 to 100 years old to wood characteristics of trees harvested at the age of 40 to 60 years. Comparisons of differences in domestic log grades suggest that the proportion of log volume in the higher grades (Special Mill and No. 2 Sawmill) increased with both stand age and tree size. Simulation of lumber grade yields based on log characteristics suggests that yields of higher grades of lumber increased until about...

The literature on ecosystem management has articulated the need for integration across disciplines and spatial scales, but convincing demonstrations of integrated analysis to support ecosystem management are lacking. This paper focuses on integrated ecological assessment because ecosystem management fundamentally is concerned with integrated management, which presupposes integrated analysis. Knowledge-based solutions are particularly relevant to ecosystem management because the topic is conceptually broad and complex and involves many abstract concepts whose assessment depends on many...

Modern ecology often emphasizes the distinction between traditional theories of stable, environmentally structured communities and a new paradigm of disturbance driven, nonequilibrium dynamics. However, multiple hypotheses for observed vegetation patterns have seldom been explicitly tested. We used multivariate statistics and variation partitioning methods to assess the relative influences of environmental factors and disturbance history on riparian and hillslope forests. Our study area was the Cummins Creek Wilderness, located in the Oregon Coast Range. Most of the wilderness burned at...

This paper documents methods for assessing the potential effects of variable-intensity management in late-successional reserves (LSRs) and provides an example (the Gotchen LSR) from the Cascade Range in eastern Washington. The Gotchen LSR study investigates changes in forest vegetation associated with silvicultural treatments, and how different treatment combinations may affect landscape patterns, LSR habitat objectives, fire hazard, and the characteristics and value of wood removed over space and time. The study contributes to the conceptual and technical development of a decision-analysis...

Seft and cross families from three populatons (A, low-density, ecologically marginal site for lodgepole pine, and B + C, normal sites) were cultured in a common outdoor nursery for 2 yrs. Previous results results had shown higher natural selfing rates and lower inbreeding depression in embryo survival in A than in B + C. In the nursery test, selfing decreased means of size traits, retarded phenological development, increased variance among families within populations, increased the coefficient of within-family variance, and increased within-family skewness. The selfing depression of mean...

We present 27-year results from a comparison of clear-cutting and shelterwood harvesting in the boreal forest of Alaska. Three patch clearcut and three shelterwood units were harvested in 1972; about 100 dispersed white spruce (Picea glauca (Moench) Voss) leave trees per hectare were retained in the shelterwoods. Units were mechanically scarified and an exceptionally large seed-crop was dispersed that year. Shelterwood trees were removed after 15 years. After 27 years, overstory treatment had no effect on the density or growth of the species we studied, while scarification had highly...

Fertilizer trials in coast Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) in the Oregon Coast Range usually indicate small and statistically nonsignificant response to nitrogen (N) fertilizers. Inherently weak experimental designs of past trials could make them too insensitive to detect growth differences that actually exist. Ability to detect real differences among treatments should be improved by having more than two replications per treatment and by using covariance analysis to adjust observed treatment means for unequal starting conditions among experimental treatment...

The ongoing development of sophisticated fire behavior and effects models has demonstrated the need for a comprehensive system of fuel classification that more accurately captures the structural complexity and geographic diversity of fuelbeds. The Fire and Environmental Research Applications Team (FERA) of the USD Forest Service, Pacific Northwest Research Station, is developing a national system of fuel characteristic classification (FCC). The system is designed to accommodate researchers and managers operating at a variety of scales, and who have access to a variety of kinds of input...

This paper provides an assessment of the competitive position of the forest products sector in southeast Alaska relative to that of its major competitors. An analytical framework relying on the economic concepts of comparative and competitive advantage is first developed, with emphasis on the relative cost and productivity of productive inputs such as labor, capital, and raw materials. The assessment is divided into three main components: (1) forest resource characteristics and production costs in the logging sector, (2) production costs in the sawmill sector, and (3) relative market...