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Displaying 15,071 - 15,080 of 65,164 Publications- Ecosystem physical structure, defined by the quantity and spatial distribution of biomass, influences a range of ecosystem functions. Remote sensing tools permit the non-destructive characterization of canopy and root features, potentially providing opportunities to link above- and belowground structure at fine spatial resolution in functionally meaningful ways. To test this possibility, we employed ground-based portable canopy LiDAR (PCL) and ground penetrating radar (GPR) along co-located transects in forested sites spanning multiple stages of ecosystem development and, consequently, of...AuthorsBrady Hardiman, Christopher Gough, John Butnor, Gil Bohrer, Matteo Detto, Peter CurtisSourceRemote SensingYear2017
- Forests can partially offset greenhouse gas emissions and contribute to climate change mitigation, mainly through increases in live biomass. We quantified carbon (C) density in 20 managed longleaf pine (Pinus palustris Mill.) forests ranging in age from 5 to 118 years located across the southeastern United States and estimated above-and belowground C trajectories. Ecosystem C stock (all pools including soil C) and aboveground live tree C increased nonlinearly with stand age and the modeled asymptotic maxima were 168 Mg C/ha and 80 Mg C/ha, respectively. Accumulation of ecosystem C with...AuthorsLisa J. Samuelson, Thomas A. Stokes, John Butnor, Kurt Johnsen, Carlos A. Gonzalez-Benecke, Timothy A. Martin, Wendell P. Cropper, Pete H. Anderson, Michael R. Ramirez, John C. LewisKeywordsSourceEcological ApplicationsYear2017
- Societies use biologically active chemicals as medicines and pesticides to protect human and agricultural health. But widespread use of synthetic compounds raises concerns about their safety, and resistance development in targeted pests. To find safer alternatives, scientists turned to native plants and trees in Pacific Northwest forests using multiyear exploratory surveys. Researchers collected samples from different plant and tree parts for extraction and toxicity testing with a simple brine shrimp bioassay. These bioassays detected strong biological activity in heartwood extracts from...AuthorsNatasha Vizcarra, Rick G. Kelsey, Joe KarchesySourceScience Findings 194. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 5 p.Year2017
- The evapotranspiration / potential evapotranspiration (AET / PET) ratio is traditionally termed as the crop coefficient (Kc) and has been generally used as ecosystem evaporative stress index. In the current hydrology literature, Kchas been widely used as a parameter to estimate crop water demand by water managers but has not been well examined for other types of ecosystems such as forests and other perennial vegetation. Understanding the seasonal dynamics of this variable for all ecosystems is important for projecting the ecohydrological responses to climate change and accurately quantifyin...AuthorsChunwei Liu, Ge Sun, Steve McNulty, Asko Noormets, Yuan FangSourceHydrology and Earth System SciencesYear2017
- This study determined total suspended sediment (TSS) at six stream crossings that represented a range of site conditions and forest operations in the Piedmont of North Carolina. Two wood and three steel bridgemats and one culvert were installed to cross the streams. The road classes for the crossings included four temporary skid trails and two permanent forest haul roads. Baseflow and stormflow water samples and continuous stream discharge were measured using the upstream-downstream approach to determine the effects of stream crossings on TSS concentrations and loads. Upstream and downstrea...AuthorsJohnny Boggs, Ge Sun, Steve McNultySourceJournal of ForestryYear2017
- For some volunteers, neighborhood safety is one of the reasons for becoming involved in community greening. For example, many volunteers of the Community Greenspace program at the Urban Resources Initiative in New Haven, Connecticut believe that there is a potential reduction in crime from community greening activities, even though it is not an explicit goal of the program. These types of community-led interventions are distinct from both existing tree canopy and large-scale municipally led initiatives. These types of interventions remain understudied with respect to the potential for...AuthorsDexter H. Locke, SeungHoon Han, Michelle Kondo, Colleen Murphy-Dunning, Mary CoxKeywordsSourceLandscape and Urban Planning. 161: 72-79.Year2017
- Browsing ungulates alter forest productivity and vegetation succession through selective foraging onspecies that often dominate early succession. However, the long-term and large-scale effects of browsing on forest succession are not possible to project without the use of simulation models. To explore the effects of ungulates on succession in a spatially explicit manner, we developed a Browse Extension that simulates the effects of browsing ungulates on the growth and survival of plant species cohorts within the LANDIS-II spatially dynamic forest landscape simulation model framework. We...AuthorsNathan R. De Jager, Patrick J. Drohan, Brian R. Miranda, Brian R. Sturtevant, Susan L. Stout, Alejandro A. Royo, Eric J. Gustafson, Mark C. RomanskiKeywordsSourceEcological Modelling. 350: 11-29.Year2017
- Elk Cervus canadensis nelsoni in the Black Hills, South Dakota, have been declining since 2006 and there is concern by resource managers and hunters that puma Puma concolor predation may be contributing to declining herds. We evaluated characteristics at sites where puma successfully killed elk in the Black Hills of South Dakota. We evaluated characteristics at coarse (79-ha plots) and fine (0.2-ha plot) scales across the landscape. Our primary objective was to obtain a better understanding of vegetation and terrain characteristics that may have facilitated greater susceptibility of elk to...AuthorsChadwick P. Lehman, Christopher T. Rota, Mark A. Rumble, Joshua J. MillspaughKeywordsSourceWildlife Biology. doi: 10.2981/wlb.00248.Year2017
- Creating a safe workplace for wildland firefighters has long been at the centre of discussion for researchers and practitioners. The goal of wildland fire safety research has been to protect operational firefighters, yet its contributions often fall short of potential because much is getting lost in the translation of peer-reviewed results to potential and intended users. When information that could enhance safety is not adopted by individuals, the potential to improve safety - to decipher the wildland fire physical or social environment and to recognise hazards - is lost. We use firefighte...AuthorsTheodore Ted Adams, Bret W. Butler, Sara H. Brown, Vita Wright, Anne E. BlackKeywordsSourceInternational Journal of Wildland Fire. 26: 107-112.Year2017
- Bark beetles are among the most devastating biotic agents affecting forests globally and several species are expected to be favored by climate change. Given the potential interactions of insect outbreaks with other biotic and abiotic disturbances, and the potentially strong impact of changing disturbance regimes on forest resources, investigating climatic drivers of destructive bark beetle outbreaks is of paramount importance. We analyzed 17 time-series of the amount of wood damaged by Ips typographus, the most destructive pest of Norway spruce forests, collected across 8 European countries...AuthorsLorenzo Marini, Bjorn Okland, Anna Maria Jonsson, Barbara J. Bentz, Allan Carroll, Beat Forster, Jean-Claude Gregoire, Rainer Hurling, Louis Michel Nageleisen, Sigrid Netherer, Hans Peter Ravn, Aaron Weed, Martin SchroederKeywordsSourceEcography. 40: 1426-1435.Year2017