Treesearch
Displaying 19,041 - 19,050 of 65,202 Publications- Occluded, or intra-aggregate, soil organic matter (SOM) comprises a significant portion of the total C pool in forest soils and often has very long mean residence times (MRTs). However, occluded C characteristics vary widely among soils and the genesis and composition of the occluded organic matter pool are not well understood. This work sought to define the major controls on the composition and MRT of occluded SOM in western U.S. conifer forest soils with specific focus on the influence of soil mineral assemblage and aggregate stability.We sampled soils from a lithosequence of four parent...AuthorsKatherine A. Heckman, Heather Throckmorton, Christopher Clingensmith, Francisco Javier González Vila, William R. Horwath, Heike Knicker, Craig RasmussenKeywordsSourceSoil Biology and BiochemistryYear2014
- The overall objective of this field study was to determine if Pinus nigra (Austrian Pine) could serve as a useful biomonitor to evaluate multi-year concentrations of total mercury (tHg) in vegetataion within southwesrern Pennsylvania. Austrian Pine has been widely planted as an ornamental and formerlay as a Christmas tree, and is now naturalized within the region. We collected needle samples annually during October 2004-2010 at 15-21 locations within a 5000-km2 study area. Because Austrian Pine trees typically retain needles for 3 years, we collected samples from 3 needle-age groups:...AuthorsRussell J. Hutnik, James R. McClenahen, Robert P. Long, Donald D. DavisSourceNortheastern NaturalistYear2014
- 1. Modelling the effects of environmental change on populations is a key challenge for ecologists, particularly as the pace of change increases. Currently, modelling efforts are limited by difficulties in establishing robust relationships between environmental drivers and population responses. 2. We developed an integrated capture–recapture state-space model to estimate the effects of two key environmental drivers (stream flow and temperature) on demographic rates (body growth, movement and survival) using a long-term (11 years), high-resolution (individually tagged, sampled seasonally)...AuthorsBenjamin H. Letcher, Paul Schueller, Ronald D. Bassar, Keith Nislow, Jason A. Coombs, Krzysztof Sakrejda, Michael Morrissey, Douglas B. Sigourney, Andrew R. Whiteley, Matthew J. O'Donnell, Todd L. DubreuilKeywordsSourceJournal of Animal EcologyYear2014
- Direct effects of climate change on animal physiology, and indirect impacts from disruption of seasonal synchrony and breakdown of trophic interactions are particularly severe in Arctic and Alpine ecosystems. Unravelling biotic from abiotic drivers, however, remains challenging because high-resolution animal population data are often limited in space and time. Here, we show that variation in annual horn growth (an indirect proxy for individual performance) of 8043 male Alpine ibex (Capra ibex) over the past four decades is well synchronised among eight disjunct colonies in the eastern...AuthorsUlf Büntgen, Andrew M. Liebhold, Hannes Jenny, Atle Mysterud, Simon Egli, Daniel Nievergelt, Nils C. Stenseth, Kurt BollmannKeywordsSourceEcology LettersYear2014
- We describe a case of paravertebral abscess caused by a Phellinus sp. in a boy with chronic granulomatous disease. Sequencebased identification of this mold, a new agent of disease, suggests a close relation to Phellinus umbrinellus.AuthorsSuk See De Ravin, Mark Parta, Deanna A. Sutton, Brian L. Wickes, Elizabeth H. Thompson, Nathan P. Wiederhold, Karen K. Nakasone, Meghna Alimchandani, Amy OConnell, Luigi Notarangelo, Elizabeth Kang, Harry L. Malech, Adrian M. ZelaznySourceJournal of Clinical MicrobiologyYear2014
- The Rocky Mountain Research Station’s 2014-2017 Strategic Business Plan presents the actions we will take to achieve our Vision and to meaningfully contribute to the needs of land managers, interested partners and the public as we support the mission of the Forest Service Research & Development (FS R&D) organization. The Business Plan serves as a communication tool between the Station‘s Leadership Team and our employees, the broader Forest Service community, and Forest Service colleagues.AuthorsNan ChristiansenKeywordsSourceFort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 28 p.Year2014
- A vision statement often describes a future state or condition to which one aspires. Such is not the case for the Station’s 2014-2017 Vision. While there is much we want to do to further enhance successful achievement of our Vision, we are well on our way.AuthorsNan ChristiansenSourceFort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 24 p.Year2014
- The future health of ecosystems is arguably as dependent on urban sprawl as it is on human caused climatic warming. Urban sprawl strongly impacts the urban ecosystems it creates and the natural and agro-ecosystems that it displaces and fragments. Here, we project urban sprawl changes for the next 50 years for the fast-growing Southeast U.S. Previous studies have focused on modeling population density, but the urban extent is arguably as important as population density per se in terms of its ecological and conservation impacts. We develop simulations using the SLEUTH urban growth model that...AuthorsAdam J. Terando, Jennifer Costanza, Curtis Belyea, Robert R. Dunn, Alexa McKerrow, Jaime A. CollazoSourcePLoS ONEYear2014
- The existence of thousands of soft-story woodframe buildings in California has been recognized as a disaster preparedness problem with concerted mitigation efforts underway in many cities throughout the state. The NEES-Soft project, whose full title is “Seismic Risk Reduction for Soft-Story Woodframe Buildings,” is a five-university multi-industry three-year project which has many facets including improved nonlinear numerical modeling, outreach, design method development, and full-scale system-level experimental validation of soft-story retrofit techniques. This paper summarizes the...AuthorsJ.W. van de Lindt, P. Bahmani, E.N. Jennings, W. Pang, E. Ziaei, G. Mochizuki, M. Gershfeld, S. Pryor, X. Shao, M. Symans, J. Tian, Douglas R. RammerKeywordsSourceProceedings of the 10th National Conference in Earthquake EngineeringYear2014
- Empirical sensitivity analyses are important for evaluation of the effects of a changing climate on water resources and ecosystems. Although mechanistic models are commonly applied for evaluation of climate effects for snowmelt, empirical relationships provide a first-order validation of the various postulates required for their implementation. Previous studies of empirical sensitivity for April 1 snow water equivalent (SWE) in the western United States were developed by regressing interannual variations in SWE to winter precipitation and temperature. This offers a temporal analog for...AuthorsCharlie H. Luce, Viviana Lopez-Burgos, Zachary HoldenKeywordsSourceWater Resources Research. 50: 9447-9462.Year2014