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Displaying 18,711 - 18,720 of 65,196 Publications- The masting phenomenon along with its accompanying suite of seedling adaptive traits has been well studied in forest trees but has rarely been examined in desert shrubs. Blackbrush (Coleogyne ramosissima) is a regionally dominant North American desert shrub whose seeds are produced in mast events and scatter-hoarded by rodents. We followed the fate of seedlings in intact stands vs. small-scale disturbances at four contrasting sites for nine growing seasons following emergence after a mast year. The primary cause of first-year mortality was post-emergence cache excavation and seedling...AuthorsSusan E. Meyer, Burton K. PendletonKeywordsSourceActa Oecologica. 65-66: 1-10.Year2015
- It is assumed that the flow of moisture in forest fuels and other woody materials is determined by the gradient of a quantity g which is a function of some property, or properties, of the moisture content. There appears to be no preferred choice for this function, hence moisture transfer equations can be based on a number of equally valid definitions of g. The physical meaning and dimensions of the mass conductivity kg will depend on the definition of g but the mass diffusivity α is independent of g. Simplified solutions to the transfer equations are expressed in terms of the ratio t/τ....AuthorsG.M. Byram, R.M. NelsonKeywordsSourcee-Gen. Tech. Rep. SRS-200. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station. 45 p.Year2015
- The southeastern United States is experiencing a rapid regional increase in the ratio of pine to deciduous forest ecosystems at the same time it is experiencing changes in climate. This study is focused on exploring how these shifts will affect the carbon sink capacity of southeastern US forests, which we show here are among the strongest carbon sinks in the continental United States. Using eight-year-long eddy covariance records collected above a hardwood deciduous forest (HW) and a pine plantation (PP) co-located in North Carolina, USA, we show that the net ecosystem exchange of CO2...AuthorsKimberly Novick, A. Christopher Oishi, Eric J. Ward, Mario B.S. Siqueira, Jehn-Yih Juang, Paul C. StoyKeywordsSourceGlobal Change BiologyYear2015
- Predation is dangerous, not only for the prey but sometimes also for the predator. Because these dangers to predators are not well understood, we document evidence of predation or scavenging by a Golden Eagle (Aquila chrysaetos) on a North American porcupine (Erethizon dorsatum) in Pennsylvania, USA, with potentially lethal consequences to the eagle. We also review published literature on incidence of porcupine quills causing injury or death to birds. At least nine species have been documented as having contact with porcupine quills. A minimum of 39% of these interactions resulted in death...AuthorsTodd Katzner, Tricia A. Miller, Jane Rodrigue, Steven ShafferKeywordsSourceThe Wilson Journal of Ornithology. 127(1): 102-108.Year2015
- The United States’ share of global industrial roundwood production has declined since the 1990s. We reviewed data from 1961-2013 to evaluate the extent of this decline for industrial roundwood and derived secondary forest products compared to other major producing countries. We find that the U.S. global share of industrial roundwood peaked at 28 percent in 1999 but then declined to 17 percent by 2012. We attribute the decline to a combination of cyclical factors, most notably the decline in U.S. construction, and long-term decline in U.S. paper manufacture that is connected to a reduction...AuthorsJeffrey P. Prestemon, David N. Wear, Michaela FosterKeywordsSourcee-Gen. Tech. Rep. SRS-204. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station. 24 p.Year2015
- In response to changing demographics and cultural shifts in the U.S. population, the Forest Service, U.S. Department of Agriculture has initiated a range of “culturally transforming” management practices and priorities aimed at better reflecting both the current and future U.S. population (USDA 2011). This makeover also calls attention to the various publics served by the Forest Service and questions whether the Agency’s services and programming are reasonably accessible by racial and ethnic minority populations within the U.S. populace. Although a priority for upper level management, the...AuthorsCassandra Johnson Gaither, Nina S. Roberts, Kristin L. HanulaKeywordsSourceGen. Tech. Rep. SRS-205. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station.Year2015
- Practical application of black carbon (biochar) to improve forest soil may be limited because biochar is hydrophobic. In a laboratory, we tested the water repellency of biochar application (mixed or surface applied) to two forest soils of varying texture (a granitic coarse-textured Inceptisol and an ash cap fine-textured Andisol) at four different application rates (0, 1, 5, and 10 Mg ha-1) and five soil moisture contents (0%, 25%, 50%, 75%, and 100% of saturation). To address the impact of biochar on water infiltration into the soil, we measured soil water repellency using three methods...AuthorsDeborah S. Page-Dumroese, Pete R. Robichaud, Bob E. Brown, Joanne M. TirockeSourceTransactions of the ASABE. 58(2): 335-342.Year2015
- Forest ecosystems in the Central Appalachians will be affected directly and indirectly by a changing climate over the 21st century. This assessment evaluates the vulnerability of forest ecosystems in the Central Appalachian Broadleaf Forest-Coniferous Forest-Meadow and Eastern Broadleaf Forest Provinces of Ohio, West Virginia, and Maryland for a range of future climates. Information on current forest conditions, observed climate trends, projected climate changes, and impacts on forest ecosystems was considered by a multidisciplinary panel of scientists, land managers, and academics in...AuthorsPatricia R. Butler, Louis Iverson, Frank R. Thompson, Leslie Brandt, Stephen Handler, Maria Janowiak, P. Danielle Shannon, Chris Swanston, Kent Karriker, Jarel Bartig, Stephanie Connolly, William D. Dijak, Scott Bearer, Steve Blatt, Andrea Brandon, Elizabeth Byers, Cheryl Coon, Tim Culbreth, Jad Daly, Wade Dorsey, David Ede, Chris Euler, Neil Gillies, David M. Hix, Catherine Johnson, Latasha Lyte, Stephen Matthews, Dawn McCarthy, Dave Minney, Daniel Murphy, Claire O’Dea, Rachel Orwan, Matthew Peters, Anantha M. Prasad, Cotton Randall, Jason Reed, Cynthia Sandeno, Thomas M. Schuler, Lesley Sneddon, Bill Stanley, Al Steele, Susan L. Stout, Randy Swaty, Jason Teets, Tim Tomon, Jim Vanderhorst, John Whatley, Nicholas ZegreKeywordsSourceGen. Tech. Rep. NRS-146. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 310 p.Year2015
- Height and diameter growth of noble fir (Abies procera Rehd.) trees included in the largest 40 stems per acre were compared in a study that included five precommercial thinning spacings plus no thinning, in each of eight replications, at elevations from 2,200 to 4,100 feet in the western Cascade Mountains of Washington and Oregon. Height growth rates were not affected by spacing. The unthinned treatment had slightly greater initial heights, a difference that probably arose from the method used to select leave trees in thinning. Height trends differed markedly from those given in Herman et...AuthorsRobert CurtisKeywordsSourceRes. Pap. PNW-RP-603. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 20 p.Year2015
- Thousand cankers disease (TCD) of walnut trees (Juglans spp.) results from aggressive feeding in the phloem by the walnut twig beetle (WTB), Pityophthorus juglandis, accompanied by inoculation of its galleries with a pathogenic fungus, Geosmithia morbida. In 1960, WTB was only known from four U.S. counties (in Arizona, California, and New Mexico), but the species has now (2014) invaded over 115 counties, representing much of the western USA, and at least six states in the eastern USA. The eastern expansion places TCD in direct proximity to highly valuable (> $500 billion) native timber...AuthorsPaul F. Rugman-Jones, Steve J. Seybold, Andrew D. Graves, Richard StouthamerSourcePLOS One. 10(2): e0118264Year2015