Treesearch
Displaying 15,401 - 15,410 of 65,182 Publications- Large trees are important to a wide variety of wildlife, including many species of conservation concern, such as the California spotted owl (Strix occidentalis occidentalis). Light detection and ranging (LiDAR) has been successfully utilized to identify the density of large-diameter trees, either by segmenting the LiDAR point cloud into individual trees, or by building regression models between variables extracted from the LiDAR point cloud and field data. Neither of these methods is easily accessible for most land managers due to the reliance on specialized software, and much available...AuthorsHeather A. Kramer, Brandon M. Collins, Lief Gallagher, John J. Keane, Scott L. Stephens, Maggi KellyKeywordsSourceEcosphere. 7(12): e01593Year2016
- Treatments to reduce forest fuels are often performed in forests to enhance forest health, regulate stand density, and reduce the risk of wildfires. Although commonly employed, there are concerns that these forest fuel treatments (FTs) may have negative impacts on certain wildlife species. Often FTs are planned across large landscapes, but the actual treatment extents can differ from the planned extents due to operational constraints and protection of resources (e.g. perennial streams, cultural resources, wildlife habitats). Identifying the actual extent of the treated areas is of primary...AuthorsYanjun Su, Qinghua Guo, Brandon M. Collins, Danny L. Fry, Tianyu Hu, Maggi KellySourceInternational Journal of Remote Sensing. 37(14): 3322-3345Year2016
- Agroforestry as a land management practice presents a method for partially offsetting greenhouse gas emissions from agricultural land. Of all agroforestry practices in the United States, windbreaks in particular are used throughout the United States providing a useful starting point for deriving a modelling systemwhich could quantify the amount of carbon sequestered on U.S. agricultural land and provide for broad usability. We present our first approximation to this end by presenting a model that estimates current and future stocks within multiple carbon pools of windbreak systems such as...AuthorsJustin Ziegler, Mark Easter, Amy Swan, James Brandle, William Ballesteros, Grant M. Domke, Adam Chambers, Marlen Eve, Keith PaustianSourceAgroforestry Systems. 90(5): 875-887.Year2016
- Spatial variation in abundance is influenced by local- and landscape-level environmental variables, but modeling landscape effects is challenging because the spatial scales of the relationships are unknown. Current approaches involve buffering survey locations with polygons of various sizes and using model selection to identify the best scale. The buffering approach does not acknowledge that the influence of surrounding landscape features should diminish with distance, and it does not yield an estimate of the unknown scale parameters.AuthorsRichard Chandler, Jeffrey Hepinstall-CymermanKeywordsSourceLandscape EcologyYear2016
- Tree mortality is an important demographic process and primary driver of forest dynamics, yet there are relatively few plot-based studies that explicitly quantify mortality and compare the relative contribution of endogenous and exogenous disturbances at regional scales. We used repeated observations on 289,390 trees in 3673 1 ha plots on U.S. Forest Service lands in Oregon and Washington to compare distributions of mortality rates among natural disturbances and vegetation zones from the mid-1990s to mid-2000s, a period characterized by drought, insect outbreaks, and large wildfires....AuthorsThomas Spies, Matthew ReillySourceForest Ecology and ManagementYear2016
- Estimates of species’ vital rates and an understanding of the factors affecting those parameters over time and space can provide crucial information for management and conservation. We used mark–recapture, reproductive output, and territory occupancy data collected during 1985–2013 to evaluate population processes of Northern Spotted Owls (Strix occidentalis caurina) in 11 study areas in Washington, Oregon, and northern California, USA. We estimated apparent survival, fecundity, recruitment, rate of population change, and local extinction and colonization rates, and investigated relationshi...AuthorsKatie M. Dugger, Eric D. Forsman, Alan B. Franklin, Raymond J. Davis, Gary C. White, Carl J. Schwarz, Kenneth P. Burnham, James D. Nichols, James E. Hines, Charles B. Yackulic, Paul F. Doherty, Larissa Bailey, Darren A. Clark, Steven H. Ackers, Lawrence S. Andrews, Benjamin Augustine, Brian Biswell, Jennifer Blakesley, Peter C. Carlson, Matthew J. Clement, Lowell V. Diller, Elizabeth M. Glenn, Adam Green, Scott A. Gremel, Dale R. Herter, J. Mark Higley, Jeremy Hobson, Rob B. Horn, Kathryn P. Huyvaert, Christopher McCafferty, Trent McDonald, Kevin McDonnell, Gail S. Olson, Janice A. Reid, Jeremy Rockweit, Viviana Ruiz, Jessica Saenz, Stan SovernKeywordsSourceThe Condor. 118(1): 57-116.Year2016
- Small-scale experiments have demonstrated that fire radiative energy is linearly related to fuel combusted but such a relationship has not been shown at the landscape level of prescribed fires. This paper presents field and remotely sensed measures of pre-fire fuel loads, consumption, fire radiative energy density (FRED) and fire radiative power flux density (FRFD), from which FRED is integrated, across forested and non-forested RxCADRE 2011 and 2012 burn blocks. Airborne longwave infrared (LWIR) image time series were calibrated to FRFD and integrated to provide FRED. Surface fuel loads...AuthorsAndrew T. Hudak, Matthew B. Dickinson, Benjamin C. Bright, Robert L. Kremens, E. Louise Loudermilk, Joseph J. O'Brien, Ben Hornsby, Roger D. OttmarKeywordsSourceInternational Journal of Wildland Fire. 25: 25-37.Year2016
- Hot water extraction (HWE) partially removes hemicelluloses from wood while leaving the majority of the lignin and cellulose; however, the lignin partially migrates to the inner surfaces of the cell wall where it can be deposited as a layer that is sometimes visible as droplets. This lignin-rich material was isolated via Soxhlet extraction with dichloromethane to investigate its rheological behavior in blends with high-density polyethylene (HDPE), a common material in wood plastic composites (WPCs). Pyrolysis gas-chromatography/mass spectrometry (Py-GC/MS) and electrospray ion mass...AuthorsManuel R. Pelaez-Samaniego, Vikram Yadama, Manuel Garcia-Perez, Eini C. Lowell, Rui Zhu, Karl EnglundKeywordsSourceHolzforschung. 70(1): 31-38.Year2016
- Recent vulnerability assessments, conducted in diverse regions in the northwestern United States, indicate that many commonalities exist with respect to projected vulnerabilities to climate change. Dry forests are projected to have significant changes in distribution and abundance of species, partially in response to higher temperature and lower soil moisture, but mostly in response to projected increases in extreme events and disturbances—drought, wildfire, and insect outbreaks. Wildfire and mountain pine beetles have caused extensive mortality across millions of hectares in this region...AuthorsJessica Halofsky, David L. PetersonSourceAtmosphere. 7(3): 46-.Year2016
- 1. Arbuscular mycorrhizal (AM) fungi can exert a powerful influence on the outcome of plant–plant competition. Since some exotic plants interact differently with soil biota such as AM fungi in their new range, range-based shifts in AM responsiveness could shift competitive interactions between exotic and resident plants, although this remains poorly studied. 2. We explored whether genotypes of the annual exotic Centaurea solstitialis (yellow starthistle), collected from populations across the native and non-native ranges, differed in responsiveness to AM fungi in the introduced range and...AuthorsLauren P. Waller, Ragan M. Callaway, John N. Klironomos, Yvette K. Ortega, John L. MaronKeywordsSourceJournal of Ecology. 104: 1599-1607.Year2016