Treesearch
Search National Treesearch
Displaying 4,021 - 4,030 of 6,855 Publications
- This paper presents a conceptual framework for ranking the crown fire potential of wildland fuelbeds with forest canopies. This approach extends the work by Van Wagner and Rothermel, and introduces several new physical concepts to the modeling of crown fire behavior derived from the reformulated Rothemel surface fire modeling concepts proposed by Sandberg et al. This framework forms the basis for calculating the crown fire potentials of Fuel Characteristic Classification System (FCCS) fuelbeds. Two new crown fire potentials are proposed (i) the torching potential (TP) and (ii) the active...AuthorsMark D. Schaaf, David V. Sandberg, Maarten D. Schreuder, Cynthia L. RiccardiSourceCanadian Journal of Forest Research. 37: 2464-2478Year2007
- This study examines the effects of bole-only harvesting with and without vegetation control (BO+VC; BO-VC) and total-tree harvesting plus removal of legacy woody debris with vegetation control (TTP+VC) on microsite soil and air temperatures in a young Douglas-fir plantation. Mean soil temperature and the diurnal range in soil temperature during the growing season differed by forest floor microsite in the following sequence: exposed mineral soil > intact forest floor > decaying wood over soil > shade of stumps. Total annual soil degree-day accumulation was 25 to 37 percent greater in the...AuthorsW.D. Devine, C.A. HarringtonKeywordsSourceAgricultural and Forest Meteorology. 145: 125-138.Year2007
- Rangeland exclosures installed primarily in the 1960s, but with some from the 1940s, were resampled for changes in plant community structure and composition periodically from 1977 to 2004 on the Malheur, Umatilla, and Wallowa-Whitman National Forests in northeastern Oregon. They allow one to compare vegetation with all-ungulate exclusion (known historically as game exclosures), all-livestock exclusion (known historically as stock exclosures), and with no exclusion (known as open areas). Thirteen upland rangeland exclosures in northeastern Oregon were selected and are presented with plant...AuthorsCharles Grier JohnsonKeywordsSourceGen. Tech. Rep. PNW-GTR-724. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 33 pYear2007
- Hemlock dwarf mistletoe (Arceuthobium tsugense [Rosendahl] G.N. Jones) is a small, inconspicuous parasite that has significant effects on tree growth and stand structure in coastal forest ecosystems of western North America. Most previous research focused on the effects of hemlock dwarf mistletoe on timber production. Previous clearcut harvesting of large areas that removed virtually all infected trees and forestry practices that established even-aged stands of trees effectively prevented or minimized future hemlock dwarf mistletoe impacts. Under this regime, further research on hemlock...AuthorsJohn A. Muir, Paul HennonSourceGen. Tech. Rep. PNW-GTR-718. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 142 pYear2007
- How do you project the effects of management decisions made today on future conditions of riparian forests, stream habitat, and fish abundance in the streams and rivers of the interior Columbia Basin? Researchers at PNW Research Station have developed some novel analytical tools to help answer this question. Their work is part of the Interior Northwest Landscape Analysis System (INLAS).AuthorsJonathan ThompsonSourceScience Findings 92. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 5 pYear2007
- 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. Current data and downloadable Excel files are available online.AuthorsDebra WarrenKeywordsSourceRes. Bull. PNW-RB-254. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 165 pYear2007
- Unlike other natural hazards such as floods, hurricanes, and earthquakes, wildfire risk has not previously been examined using a hedonic property value model. In this article, we estimate a hedonic model based on parcel-level wildfire risk ratings from Colorado Springs. We found that providing homeowners with specific information about the wildfire risk rating of their property has affected housing prices.AuthorsG.H. Donovan, P.A. Champ, D.T. ButryKeywordsSourceLand Economics. 83(2): 217-233Year2007
- During September 19-20, 2006, a conference was held at the University of Washington Botanic Gardens, Seattle, WA, with the title "Meeting the challenge: invasive plants in Pacific Northwest Ecosystems." The mission of the conference was to create strategies and partnerships to understand and manage invasions of non-native plants in the Pacific Northwest. The audience included over 180 professionals, students, and citizens from public and private organizations responsible for monitoring, studying, or managing non-native invasive plants. This proceedings includes twenty-seven papers based on...AuthorsTimothy B. Harrington, Sarah H. ReichardKeywordsSourceGen. Tech. Rep. PNW-GTR-694. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 166 pYear2007
- This study examines production rates and costs for felling and helicopter yarding on eight units harvested in accordance with ecologically based silvicultural prescriptions. The units represent five levels of basal area retention. The levels of retention had irregular spatial arrangements caused by gaps and clumps that ranged from 0 percent retention (clearcut) to 75 percent of basal area retained. Turn time, as adjusted to a standardized distance, and turn weight were used as measures of productivity. There were statistically significant differences in adjusted turn time, depending on the...AuthorsL. Christian, A. BrackleyKeywordsSourceWestern Journal of Applied Forestry. 22(2): 142-147Year2007
- Wildland fire managers deploy suppression resources to bases and dispatch them to fires to maximize the percentage of fires that are successfully contained before unacceptable costs and losses occur. Deployment is made with budget constraints and uncertainty about the daily number, location, and intensity of fires, all of which affect initial-attack success. To address the deployment problem, we formulate a scenario-based standard response model with two objective functions: the number of suppression resources deployed and the expected daily number of fires that do not receive a standard...AuthorsRobert G. Haight, Jeremy S. FriedKeywordsSourceINFOR. 45(1): 31-39Year2007