Treesearch
Search National Treesearch
Displaying 3,791 - 3,800 of 6,854 Publications
- The Northwest Forest Plan (the Plan) was developed in 1994 to resolve debates over old-growth forests and endangered species on federal forests in the range of the northern spotted owl. In 2005, federal agencies reviewed the first 10 years under the Plan to learn what worked and what did not, what changed, and what new information or surprises might influence these forests in the future. Following are some of the key findings. Nearly all existing older forest habitat on federal land was protected from timber harvest. Older forest on federal land had a net increase of over 1 million acres...AuthorsValerie RappSourceGen. Tech. Rep. PNW-GTR-720. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 42 pYear2008
- Biodiversity has been called a form of ecosystem insurance. According to the "insurance hypothesis", the presence of many species protects against system decline, because built-in redundancies guarantee that some species will maintain key functions even if others fail. The hypothesis might have merit, but calling it "insurance" promotes an ambiguous understanding of risk management strategies and underlying theories of risk. Instead, such redundancy suggests a strategy of diversification. A clearer understanding of risk includes comprehending the important distinction between risk assessmen...AuthorsSusan Hummel, Geoffrey Donovan, Thomas A. Spies, Miles HemstromSourceFrontiers in ecology and the environment. 6. DOI: 10.1890/070111.Year2008
- We examined 5-year basal area growth of nearly 2600 trees in stem-mapped plots at five locations differing in site characteristics, species composition, and management history on the Olympic Peninsula in Western Washington, USA. Our objectives were to determine if internal edges, the boundaries within the stand between components of the variable-density thinning, influenced individual tree growth, and whether incorporation of individual tree local competition indices in growth prediction models could account for treatment and edge effects. Treatment significantly affected tree growth at...AuthorsScott D.s Roberts, Constance A. HarringtonKeywordsSourceForest Ecology and Mangement. 255(7): 2771-2781.Year2008
- Broadly defined, ecosystem services are the benefits healthy ecosystems provide to humans. Clean air, clean water, and flood control are just a few examples. Although the term is relatively new, the ecosystem services concept has long been a focus of natural resource and environmental economists. As the U.S. population increases and the forests and grasslands that provide ecosystem services are threatened by development, there is growing interest among natural resource agencies, conservation groups, private landowners, and others to explore the ecosystem services concept as a way to...AuthorsSussane MalekiKeywordsSourceScience Update 16. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 12 pYear2008
- Light detection and ranging (LIDAR) is an emerging remote-sensing technology with promising potential to assist in mapping, monitoring, and assessment of forest resources. Continuous technological advancement and substantial reductions in data acquisition cost have enabled acquisition of laser data over entire states and regions. These developments have triggered an explosion of interest in LIDAR technology. Despite a growing body of peer-reviewed literature documenting the merits of LIDAR for forest assessment, management, and planning, there seems to be little information describing in...AuthorsDemetrios Gatziolis, Hans-Erik AndersenKeywordsSourceGen. Tech. Rep. PNW-GTR-768. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 32 pYear2008
- We describe methods for efficient, accurate sampling of logs at landscape and stand scales to estimate density, total length, cover, volume, and weight. Our methods focus on optimizing the sampling effort by choosing an appropriate sampling method and transect length for specific forest conditions and objectives. Sampling methods include the line-intersect method and the strip-plot method. Which method is better depends on the variable of interest, log quantities, desired precision, and forest conditions. Two statistical options are available. The first requires sampling until a desired...AuthorsLisa J. Bate, Torolf R. Torgersen, Michael Wisdom, Edward O. Garton, Shawn C. ClaboughKeywordsSourceGen. Tech. Rep. PNW-GTR-746. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 93 p.Year2008
- The USDA Forest Service implemented the National Visitor Use Monitoring (NVUM) program across the entire National Forest System (NFS) in calendar year 2000. The primary objective of the NVUM program is to develop reliable estimates of recreation use on NFS lands via a nationally consistent, statistically valid sampling approach. Secondary objectives of NVUM are to characterize recreation visits, collect data in support of regional economic analyses, and gauge national forest visitor satisfaction. We document and review the round 1 NVUM implementation in the USDA Forest Service Alaska...AuthorsEric M. White, Joshua B. WilsonSourceGen. Tech. Rep. PNW-GTR-740. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 52 pYear2008
- The demand for water is rapidly increasing, but the uses to which that water is put and the values society places on water are changing dramatically. Water is the source of life, the sustenance for living, the resource needed for manufacturing, mining, agriculture; the element required to grow our lawns, to water our landscaping, to shower us with refreshment; it is the place where we play; it provides the snow for our winter recreation, and it provides the habitat for much of our wildlife. Water in contemporary American society is more than a simple physical entity, its symbolic values,...AuthorsStephen F. McCool, Roger N. Clark, George H. StankeyKeywordsSourceGen. Tech. Rep. PNW-GTR-729. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 246 pYear2008
- As I look back at 2007 for the Pacific Northwest (PNW) Research Station, I am very gratified at the contributions of our scientists and support staff in producing scientific knowledge and tools. This year has brought unprecedented recognition of the contributions of our scientists. Ralph Alig (research forester), Ron Neilson (bioclimatologist), and David L. Peterson (research biologist) were recognized with the Nobel Peace Prize for their contributions to the International Panel on Climate Change. Their participation in this rigorous endeavor is truly remarkable. They and those who have...AuthorsRhonda MazzaSourceScience Accomplishments Report of the Pacific Northwest Research Station. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 88 p.Year2008
- Detecting changes in forest soil C and N is vital to the study of global budgets and long-term ecosystem productivity. Identifying differences among land-use practices may guide future management. Our objective was to determine the relation of minimum detectable changes (MDCs) and minimum detectable differences between treatments (MDDs) to soil C and N variability at multiple spatial scales. The three study sites were 70- to 100-year-old coniferous forests in Washington and Oregon. Area- and volumetric-based soil measurements were made before implementation of seven treatments on 2-ha...AuthorsP.S. Homann, B.T. Bormann, J.R. Boyle, R.L. Darbyshire, R. BigleyKeywordsSourceForest Ecology and Management. 255: 1724-1734Year2008