Treesearch

Commercial matsutake mushroom (Tricholoma magnivelare) harvest in the Pacific Northwest is common in Lodgepole Pine (Pinus contorta) forests. Insuffi cient ecological knowledge of the mycorrhizae and mycelium has challenged monitoring of this resource. Among many management issues are concerns over logging practices, a lack of information on the ecology and habitat requirements of American Matsutake, and the potential eff ects of the type and intensity of matsutake harvest on future mushroom productivity. Lodgepole Pine and mixed-conifer stands provide habitat for growing and harvesting...

Increasing global demands on forest resources are driving large-scale shifts toward plantation forestry. Simultaneously balancing resource extraction and ecological sustainability objectives in plantation forests requires the incorporation of innovative silvicultural strategies such as leave islands (green-tree retention clusters). Our primary research goal was to determine how leave islands provide refugia for low-mobility, ecologically sensitive species in managed forests of the Pacifi c Northwest, USA. We examined patterns in vascular plant, arthropod, amphibian, and mollusk assemblages...

In recent years, forest management in the Pacifi c Northwest has shifted from one based largely on resource extraction to one based on ecosystem management principles. Forest management based on these principles involves simultaneously balancing and sustaining multiple forest resource values, including silvicultural, social, economic, and ecological objectives. Leave islands, or green-tree retention clusters, have been proposed as an alternative silvicultural strategy designed to sustain the ecological integrity and biological diversity within intensively managed forests. However, pertinent...

Fiber tilt describes the projection of fiber length in the thickness direction of paper. The projection is described by the tilt angle of fibers with respect to the plane of the sheet. A simple model for fiber tilt is based on jet-to-wire velocity differential in combination with cross-flows on the wire. The tilt angle of a fiber is found to vary as the sine of its in-plane orientation angle. The phase of variation is a large multiple of the fiber-misalignment angle associated with the cross flow. The multiple can decrease from 40 to 8 as the cross-flow angle increases from 1° to 10°,...

Presentation Abstract Old-growth Douglas-fi r (Pseudotsuga menziesii) forests are a goal for conservation and restoration across millions of acres of federal forest lands in western Oregon and Washington. Where old growth currently exists, management is typically focused on protecting stands and watersheds from logging and high-severity wildfi re. Where old growth was converted to Douglas-fi r plantations during the 20th century, the goal is often to actively manage those areas to create ecological diversity and accelerate development of old-growth conditions. What does it mean to use old...

Th inning stands (managing their densities) aff ects the development of trees and understory plants as individuals, as well as stand-level characteristics like structure, microclimate, and stand growth, habitat for various species, and fuel and potential fi re severity. Th ese characteristics and the rate of changes are aff ected by thinning severity—the reduction in numbers of trees, the stand density, and also by the number, sizes, species, and growth rates of the trees retained. In addition, site variables like potential for severe wind and ice/snow storms, soil depth/rooting, root...

To understand the impacts of overstory density reductions on resilience of forest ecosystems (i.e., the capacity of an ecosystem to maintain desired ecosystem functions in a fl uctuating environment), we examined overstory basal area and understory vegetation cover and richness collected 6 years after thinning in seven 40- to 60-year-old forests dominated by Douglas-fi r (Pseudotsuga menziesii (Mirb.) Franco) in the Oregon Coast Range and Cascade Range of western Oregon. Each site contained an unthinned control (240–1,540 trees∙ha-1 [tph]) and three thinning treatment units (high-density =...

Public agencies in the Pacifi c Northwest have engaged in managing for late-successional features or structure on lands which also have the possibility for high timber production. Th is study examined the potential for developing understory structure while maintaining a productive overstory on two sites (Willamette Valley foothills and coastal) in western Oregon. Treatments included thinning 50- to 55-year-old Douglas-fi r (Pseudotsuga menziesii) or Douglas-fir/Western Hemlock (Tsuga heterophylla) stands to three or four overstory densities 30 to 65 percent below full stocking, either in a...

This paper describes a study that was undertaken to evaluate the degree of correlation between in-service performance of hardboard siding and its performance in the industry standard test procedure for “weatherability of substrate.” The study included 13 different hardboard sidings: 6 noncommercial boards and 7 commercial products. All manufacturing plants operating in the United States in 1996–1997 were represented in the study. Twenty replicate specimens of each of the 13 different boards were exposed on the south side of an unconditioned building near Madison, Wisconsin, for 155 months...