Treesearch
Displaying 14,971 - 14,980 of 65,164 Publications- The physical properties and dimensions of foliage are necessary inputs for some fire spread models. Currently, almost no data exist on these plant characteristics to fill this need. In this report, we measured the physical properties and dimensions of the foliage from 10 live shrub and conifer fuels throughout a 1-year period. We developed models to predict relative moisture content, apparent density, length, width, needle length, thickness, stem diameter, and surface area. Seasonal variability of the response variables was found to be adequately explained with a single model, so season-spe...AuthorsJonathan R. Gallacher, Thomas H. Fletcher, Victoria Lansinger, Sydney Hansen, Taylor Ellsworth, David R. WeiseKeywordsSourceRes. Pap. PSW-RP-269. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 43 p.Year2017
- Although the American pika (Ochotona princeps) continues to receive attention due to documented declines and range retractions, particularly in the Great Basin, thorough range inventories have yet to be completed in many parts of the region. Here we report on recently discovered populations in northwestern Nevada in areas not suspected to support pika activity under current climate regimes. We describe 238 new locations (“sites”) with evidence of past or current occupancy by pikas that cluster into 31 locales, which we interpret as metapopulations or “demes”, in 15 distinct mountain ranges...AuthorsMackenzie R. Jeffress, K. Jane Van Gunst, Connie I. MillarKeywordsSourceWestern North American Naturalist. 77Year2017
- To evade endangered timber species laws, unscrupulous importers sometimes attempt to pass protected Dalbergia nigra as look-alike but unprotected, Dalbergia Spruceana. Wood density and fluorescence properties are sometimes used to identify the species. Although these properties are useful and do not require special equipment, they may be less reliable than direct analysis in real time—time of flight mass spectrometry (DART—TOFMS). DART—TOFMS was used to check identities of the D. nigra and D. Spruceana contained in the wood collection of the Forest Products Laboratory (Madison, Wisconsin)....AuthorsMichael C. Wiemann, Edgard O. EspinozaKeywordsSourceResearch Paper FPL–RP–690. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 10 p.Year2017
- We review the mechanisms of deleterious nitrogen (N) deposition impacts on temperate forests, with a particular focus on trees and lichens. Elevated anthropogenic N deposition to forests has varied effects on individual organisms depending on characteristics both of the N inputs (form, timing, amount) and of the organisms (ecology, physiology) involved. Improved mechanistic knowledge of these effects can aid in developing robust predictions of how organisms respond to either increases or decreases in N deposition. Rising N levels affect forests in micro- and macroscopic ways from physiologi...AuthorsTherese S. Carter, Christopher M. Clark, Mark E. Fenn, Sarah Jovan, Steven S. Perakis, Jennifer Riddell, Paul Schaberg, Tara L. Greaver, Meredith G. HastingsKeywordsSourceEcosphere. 8(3): e01717Year2017
- The goal of this study was to update life-cycle assessment (LCA) data associated with I-joist production in the Pacific Northwest (PNW) region of the United States from cradle-to-gate mill output. The authors collected primary mill data from I-joist production facilities per Consortium on Research for Renewable Industrial Materials (CORRIM) research guidelines. Comparative assertions were not a goal of this study.AuthorsRichard Bergman, Sevda Alanya-RosenbaumKeywordsSourceCORRIM Final Report, Module F1. Seattle, WA: University of Washington. 1-110.Year2017
- Highbush blueberry (Vaccinium corymbosum L.) is an important crop grown throughout Florida. Currently, most blueberry growers use honey bees (Apis mellifera L.) to provide pollination services for highbush blueberries even though bumble bees (Bombus spp.) have been shown to be more efficient at pollinating blueberries on a per bee basis. In general, contribution of bumble bees to the pollination of commercial highbush blueberries in Florida is unknown. Herein we determined if managed bumble bees could contribute to highbush blueberry pollination. There were four treatments in this study:...AuthorsJ. W. Campbell, Joseph J. O'Brien, J. H. Irvin, C. B. Kimmel, J. C. Daniels, J. D. EllisSourceEnvironmental EntomologyYear2017
- The southern pine beetle has shown a dramatic decline in outbreak activity over much of the southeastern States since the turn of the 21st century compared to previous decades. Concurrently, from the 1950s through the present day, a twenty-fold increase in pine plantation area has occurred across the region while trends in genetic tree improvement and pine silvicultural advances have seen a marked increase in application towards the end of the 20th century. We examine southern pine beetle outbreaks in the Piedmont and Coastal Plain physiographic provinces of the southeastern U.S. relative...AuthorsChristopher Asaro, John Nowak, Anthony ElledgeKeywordsSourceForest Ecology and ManagementYear2017
- This report presents a summary of the most recent inventory of Colorado’s forests based on field data collected between 2004 and 2013. The report includes descriptive highlights and tables of area, numbers of trees, biomass, carbon, volume, growth, mortality, and removals. Most sections and tables are organized by forest type or forest-type group, species group, diameter class, or owner group. The report also describes the inventory’s design, inventory terminology, and data reliability. Results show that Colorado’s forest land covers 22.9 million acres. Forty-nine percent (11.1 million...AuthorsMichael T. Thompson, John D. Shaw, Christopher Witt, Charles E. Werstak, Michael C. Amacher, Sara A. Goeking, R. Justin DeRose, Todd A. Morgan, Colin B. Sorenson, Steven W. Hayes, James S. MenloveKeywordsSourceResour. Bull. RMRS-RB-23. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 136 p.Year2017
- Wild and prescribed fire-induced injury to forest trees can produce immediate or delayed tree mortality but fire-injured trees can also survive. Land managers use logistic regression models that incorporate tree-injury variables to discriminate between fatally injured trees and those that will survive. We used data from 4024 ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and 3804 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees from 23 fires across Oregon and Washington to assess the discriminatory ability of 21 existing logistic regression models and a polychotomous key (Scott...AuthorsLisa M. Ganio, Robert ProgarKeywordsSourceForest Ecology and Management. 2017. 390: 47-67Year2017
- Climate change is one of several threats that will increase the likelihood that forest tree species could experience population-level extirpation or species-level extinction. Scientists and managers from throughout the United States Forest Service have cooperated to develop a framework for conservation priority-setting assessments of forest tree species. This framework uses trait data and predictions of expected climate change pressure to categorize and prioritize 339 native tree species for conservation, monitoring, management and restoration across all forested lands in the contiguous...AuthorsKevin M. Potter, Barbara S. Crane, William HargroveKeywordsSourceNew ForestsYear2017