Treesearch
Displaying 10,681 - 10,690 of 64,772 Publications- Restoration of fire-dependent forests is often guided by reference conditions from forests with an active fire regime, thought to be resilient to current and future disturbances and stresses. Reference conditions are usually based on historical data or reconstruction, which greatly limits the scale and completeness of data that can be collected. In the Sierra Nevada of California, large areas with reintroduced active fire regimes coupled with extensive lidar data coverage provide the unique opportunity to develop a contemporary regional reference condition dataset across a wide gradient of...AuthorsSean M.A. Jeronimo, Van R. Kane, Derek J. Churchill, James A. Lutz, Malcolm P. North, Gregory P. Asner, Jerry F. FranklinSourceForest Ecology and Management. 437: 70-86Year2019
- Frameworks for limiting ecosystem exposure to excess nutrients and acidity require accurate and complete deposition budgets of reactive nitrogen (Nr). While much progress has been made in developing total Nr deposition budgets for the U.S., current budgets remain limited by key data and knowledge gaps. Analysis of National Atmospheric Deposition Program Total Deposition (NADP/TDep) data illustrates several aspects of current Nr deposition that motivate additional research. Averaged across the continental U.S., dry deposition contributes slightly more (55%) to total deposition than wet...AuthorsR.V. Pouyat, M. Puchalski, H.O.T. Pye, A.W. Rea, M.F. Rhodes, C.M. Rogers, R. Saylor, R. Scheffe, B.A. Schichtel, D.B. Schwede, G.A. Sexstone, B.C. Sive, R. Sosa, P.H. Templer, T. Thompson, D. Tong, G.A. Wetherbee, T.H. Whitlow, Z. Wu, Z. Yu, L. Zhang, J.T. Walker, G. Beachley, H.M. Amos, J.S. Baron, J. Bash, R. Baumgardner, M.D. Bell, K.B. Benedict, X. Chen, D.W. Clow, A. Cole, J.G. Coughlin, K. Cruz, R.W. Daly, S.M. Decina, E.M. Elliott, Mark E. Fenn, L. Ganzeveld, K. Gebhart, S.S. Isil, B.M. Kerschner, R.S. Larson, T. Lavery, G.G. Lear, T. Macy, M.A. Mast, K. Mishoe, K.H. Morris, Pamela E. PadgettKeywordsSourceScience of The Total Environment. 691: 1328-1352Year2019
- Historically the primary interest area for national inventories was timber. Consequently, the national inventory framework and collection protocols were focused on productive timberlands (USDA Forest Service 2005). Over time, information such as estimations of carbon sequestration, wildfire fuel loads, and nontimber forest products and services (e.g., biofuels and wildlife habitat) has become topics of increasing interest. The FIA program—the national inventory used in the United States—broadened the focus of its surveys to include nontimberland forests, including woodlands, better...AuthorsKerry DooleySourceIn: Oswalt, Sonja N.; Smith, W. Brad; Miles, Patrick D.; Pugh, Scott A., coords. 2019. Forest Resources of the United States, 2017: a technical document supporting the Forest Service 2020 RPA Assessment. Gen. Tech. Rep. WO-97. Washington, DC: U.S. Department of Agriculture, Forest Service, Washington Office.Year2019
- Downscaled climate projections need to be linked to downscaled projections of population and economic growth to fully develop implications for land, natural resources, and ecosystems for future scenarios. We develop an empirical spatiotemporal approach for jointly projecting population and income at the county scale in the United States that is consistent with neoclassical economic growth theory and overlapping labor markets and that accounts for labor migration and spatial spillovers. Downscaled projections generated for the five Shared Socioeconomic Pathways used to support global...AuthorsJeffrey P. Prestemon, David N. WearSourcePLOS ONEYear2019
- Despite the important role vegetation plays in the global water cycle, the exact controls of vegetation water use, especially the role of soil biogeochemistry, remain elusive. In this study, we reveal a new mechanism of soil biogeochemical control of large-scale vegetation water use. Nitrate and sulfate deposition from fossil fuel burning have caused substantial soil acidification, leading to the leaching of soil base cations. Of these, calcium has a unique role in plant cells by regulating stomatal aperture, thus affecting vegetation water use. We hypothesized that the leaching of the...AuthorsMatthew Lanning, Lixin Wang, Todd M. Scanlon, Matthew A. Vadeboncoeur, Mary Beth Adams, Howard E. Epstein, Daniel DruckenbrodKeywordsSourceScience AdvancesYear2019
- Premise of the Study Over one‐third of the native flowering plant species in the Hawaiian Islands are listed as federally threatened or endangered. Lack of sufficient pollination could contribute to reductions in populations, reproduction, and genetic diversity among these species but has been little studied. Methods We used systematic observations and manual flower treatments to quantify flower visitation and outcrossing dependency of eight native (including four endangered) plant species in a dryland ecosystem in Hawaii: Argemone glauca, Bidens menziesii, Dubautia linearis, Haplostachys...AuthorsClare E. Aslan, Aaron B. Shiels, William Haines, Christina LiangKeywordsSourceAmerican Journal of Botany. 106(2): 313-324Year2019
Promise and pitfalls of endemic resistance for cultural resources threatened by Phytophthora ramorum
Invasive forest pathogens can harm cultural, economic, and ecological resources. Here, we demonstrate the potential of endemic tree pathogen resistance in forest disease management using Phytophthora ramorum, cause of sudden oak death, in the context of management of tanoak (Notholithocarpus densiflorus), an ecologically unique and highly valued tree within Native American communities of northern California and southern Oregon in the United States. We surveyed resistance to P. ramorum on the Hoopa Valley Indian Reservation and Yurok Indian Reservation in a set of study sites with variable...AuthorsRichard C. Cobb, Noam Ross, Katherine Hayden, Catherine A. Eyre, Richard S. Dodd, Susan J. Frankel, Matteo Garbelotto, David M. RizzoSourcePhytopathology. 109(5): 760-769Year2019- In this study we identify pyrolysis gases from prescribed burns conducted in pine forests with a shrub understory captured using a manual extraction device. The device selectively sampled emissions ahead of the flame front, minimizing the collection of oxidized gases, with the captured gases analyzed in the laboratory using infrared (IR) absorption spectroscopy. Results show that emission ratios (ERs) relative to CO for ethene and acetylene were significantly greater than in previous fire studies, suggesting that the sample device was able to collect gases predominantly generated prior to...AuthorsJoseph Restaino, N. K. Scharko, A. M. Oeck, T. L. Myers, R. G. Tonkyn, C. A. Banach, S. P. Baker, Emily N. Lincoln, Joey Chong, Bonni M. Corcoran, Gloria M. Burke, Roger D. Ottmar, David R. Weise, T. J. JohnsonSourceAtmospheric Chemistry and Physics. 19(15): 9681-9698.Year2019
- Planning for sustainable landscapes is hampered by uncertainty in how species will respond to conservation actions amidst impacts from landscape and climate change. Planning decisions, including tradeoffs among competing species objectives, are complex. We developed a decision-support framework that integrates dynamic-landscape metapopulation models (DLMPs) and structured decision making (SDM) to help guide landscape conservation design. With this framework, we demonstrated that planning for viable populations across broad scales can be achieved under global change. Furthermore, the...AuthorsThomas W. Bonnot, D. Todd Jones-Farrand, Frank R. Thompson, Joshua J. Millspaugh, Jane A. Fitzgerald, Nate Muenks, Phillip Hanberry, Esther Stroh, Larry Heggemann, Allison Fowler, Mark Howery, Shea Hammond, Kristine EvansKeywordsSourceGen. Tech. Rep. NRS-190. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 66 p.Year2019
- Mechanical fuel treatments are machine activities designed to change the size and arrangement of forest biomass by either severing stems and creating smaller fragments (mastication) or by removing these stems from the site (bundling, baling, biomass harvesting) for disposal or utilization. Cost of mechanical fuel reduction treatments is defined as the money spent in mechanical fuel reduction activities.AuthorsDana Mitchell, Mathew F. SmidtKeywordsSourceEncyclopedia of Wildfires and Wildland-Urban Interface (WUI) Fires. Springer, Cham.Year2019