Treesearch
Displaying 20,241 - 20,250 of 65,202 Publications- An experiment designed to evaluate the treatment effects of salvaging merchantable fire-killed trees on surface fuels and regeneration was established after a wildfire in northeastern California. The study was then monitored for 10 years. Surface fuel accumulations were rapid, corresponding with a high rate of snag decay and subsequent breakage or windthrow. Pine snags retained exhibited the fastest rates of breakage and transition to surface fuels, while white fir and incense-cedar were much more stable for the duration of this study. Natural regeneration observed following salvage was...AuthorsMartin Ritchie, Eric E. KnappKeywordsSourceJournal of Forestry. 112(5): 395-400Year2014
- The US Department of Agriculture (USDA) Forest Service Blacks Mountain Experimental Forest is a 4,000 ha, pine-dominated tract in northeastern California, in the Lassen National Forest. Between 1934 and 1960 research at Blacks Mountain focused on various methods of harvest and bark beetle activity. These studies demonstrated the effectiveness of harvesting on tree growth and reducing widespread mortality from bark beetles. After a period of inactivity, research efforts accelerated in the early 1990s when a large-scale interdisciplinary research program was initiated, building on the...AuthorsMartin Ritchie, Carl SkinnerKeywordsSourceUSDA Forest Service experimental forests and ranges, research for the long term. New York: Springer: 129-146Year2014
- These maps depict the distribution of 12 tree species across the state of New York. The maps show where these trees do not occur (gray), occasionally occur (pale green), are a minor component (medium green), are a major component (dark green), or are the dominant species (black) in the forest, as determined by that species' total basal area. Basal area is the area of a cross-section of the trunk at 4.5 feet above ground (breast height). Basal area is a way of measuring how dominant a particular species is in a stand because of the way large trees contribute more to the total basal area...AuthorsRachel Riemann, Barry T. (Ty) Wilson, Andrew J. Lister, Oren Cook, Sierra Crane-MurdochSourceResearch Map NRS-5. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. [map; ~ 1:3,900,000].Year2014
- Visitation to the major nature-based national parks has been declining. This paper specifies an econometric model that estimates the relative impact of consumer incomes, travel costs, entry fees and other factors on per capita attendance from 1993 to 2010. Results suggest that entrance fees have had a statistically significant but small impact on per capita attendance. Increasing fuel prices (travel costs) relative to income has had a more significant effect suggesting that park policies reducing the cost of attendance may be desirable.AuthorsThomas H. Stevens, Thomas A. More, Marla Markowski-LindsayKeywordsSourceJournal of Leisure Research. 46(2):153-164.Year2014
- Cross-laminated Timber (CLT) has been extensively used in Europe and is now gaining momentum in North America; both Canada and more recently the U.S. Construction projects have shown that CLT can effectively be used as an alternative construction material in mid-rise structures and has significant potential in commercial and industrial buildings. In the United States, the CLT system is not currently recognized in seismic design codes and therefore a seismic design can only be performed through alternative methods specified in the codes. The FEMA P695 report published in 2009 presents a...AuthorsM. Omar Amini, John W. van de Lindt, Shiling Pei, Douglas R. Rammer, Phil Line, Marjan PopovskiSourceIn: Materials and Joints in Timber Structures, RILEM Bookseries, Volume 9, Recent Developments of Technology; 2014; 13 p.Year2014
- Forest ecosystems across the Northwoods will face direct and indirect impacts from a changing climate over the 21st century. This assessment evaluates the vulnerability of forest ecosystems in the Laurentian Mixed Forest Province of northern Wisconsin and western Upper Michigan under a range of future climates. Information on current forest conditions, observed climate trends, projected climate changes, and impacts to forest ecosystems was considered in order to assess vulnerability to climate change. Upland spruce-fir, lowland conifers, aspen-birch, lowland-riparian hardwoods, and red...AuthorsMaria Janowiak, Louis Iverson, David J. Mladenoff, Emily Peters, Kirk R. Wythers, Weimin Xi, Leslie Brandt, Patricia R. Butler, Stephen Handler, P. Danielle Shannon, Chris Swanston, Linda R. Parker, Amy J. Amman, Brian Bogaczyk, Christine Handler, Ellen Lesch, Peter B. Reich, Stephen Matthews, Matthew Peters, Anantha M. Prasad, Sami Khanal, Feng Liu, Tara Bal, Dustin Bronson, Andrew Burton, Jim Ferris, Jon Fosgitt, Shawn Hagan, Erin Johnston, Evan Kane, Colleen Matula, Ryan O'Connor, Dale Higgins, Matt St. Pierre, Jad Daley, Mae Davenport, Marla R. Emery, David Fehringer, Christopher L. Hoving, Gary Johnson, David Neitzel, Michael Notaro, Adena Rissman, Chadwick Rittenhouse, Robert ZielKeywordsSourceGen. Tech. Rep. NRS-136. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 247 p.Year2014
- The effects of plasma exposure and vacuum-ultraviolet (VUV) irradiation on the mechanical properties of low-k porous organosilicate glass (SiCOH) dielectric films were investigated. Nanoindentation measurements were made on SiCOH films before and after exposure to an electron-cyclotron-resonance plasma or a monochromatic synchrotron VUV beam, to determine the changes of film hardness, elastic modulus, and crack threshold due to these exposures. This permits the effects of ion bombardment and photon bombardment to be analyzed separately. The role of energetic ions was examined with a...AuthorsX. Guo, Joseph Jakes, S. Banna, Y. Nishi, J.L. ShohetKeywordsSourceJournal of Applied Physics 116, 2014; pp. 044103; 1-9.Year2014
- Water uptake in porous low-k dielectrics has become a significant challenge for both back-end-of-the-line integration and circuit reliability. This work examines the effects of water uptake on the fracture behavior of nanoporous low-k organosilicate glass. By using annealing dehydration and humidity conditioning, the roles of different water types and their concentrations are analyzed in detail. For as-deposited SiCOH films, annealing dehydration can enhance the resistance to crack occurrence, and these enhancements can be offset by higher humidity conditioning. It was found that the...AuthorsXiangyu Guo, Joseph Jakes, Samer Banna, Yoshio Nishi, J. Leon ShohetKeywordsSourceJournal of Vacuum Science & Technology A 32, 2014; pp. 031512 1-8.Year2014
- Wildland fire affects both public and private resources throughout the United States. A century of fire suppression has contributed to changing ecological conditions and accumulated fuel loads. Managers have used a variety of approaches to address these conditions and reduce the likelihood of wildland fires that may result in adverse ecological impacts and threaten communities. Public acceptance is a critical component of developing and implementing successful management programs. This study examines the factors that influence citizen support for agency fuel reduction treatments over...AuthorsEric Toman, Bruce Shindler, Sarah M. McCaffrey, James BennettSourceEnvironmental Management. 54(3): 557-570.Year2014
- In this study, we used a replicated factorial design to separate the individual and interacting effects of two main components of a severe hurricane – canopy opening and green debris deposition on leaf litter decay in the tabonuco forest in the Luquillo Mountains of Puerto Rico. We quantify changes in percent mass remaining (PMR), the concentration and absolute amounts of various chemical elements using fresh (green) and senesced leaf litter contained in litterbags of two different mesh sizes. Mass loss was significantly slowed by canopy trimming. There was no significant effect of debris...AuthorsGrizelle Gonzalez, D. Jean Lodge, B.A. Richardson, M.J. RichardsonKeywordsSourceForest Ecology and Management. 332:32-46.Year2014