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Displaying 7,981 - 7,990 of 64,797 Publications- Globally, soils store two to three times as much carbon as currently resides in the atmosphere, and it is critical to understand how soil greenhouse gas (GHG) emissions and uptake will respond to ongoing climate change. In particular, the soil-to-atmosphere CO2flux, commonly though imprecisely termed soil respiration (RS), is one of the largest carbon fluxes in the Earth system. An increasing number of high-frequency RSmeasurements (typically, from an automated system with hourly sampling) have been made over the last two decades; an increasing number of methane measurements are being made...AuthorsBen Bond-Lamberty, Danielle S. Christianson, Avni Malhotra, Stephanie C. Pennington, Debjani Sihi, Amir AghaKouchak, Hassan Anjileli, M. Altaf Arain, Juan J. Armesto, Samaneh Ashraf, Mioko Ataka, Dennis Baldocchi, Thomas Andrew Black, Nina Buchmann, Mariah S. Carbone, Shih‐Chieh Chang, Patrick Crill, Peter S. Curtis, Eric A. Davidson, Ankur R. Desai, John E. Drake, Tarek S. El‐Madany, Michael Gavazzi, Carolyn‐Monika Görres, Christopher M. Gough, Michael Goulden, Jillian Gregg, Omar Gutiérrez del Arroyo, Jin‐Sheng He, Takashi Hirano, Anya Hopple, Holly Hughes, Järvi Järveoja, Rachhpal Jassal, Jinshi Jian, Haiming Kan, Jason Kaye, Yuji Kominami, Naishen Liang, David Lipson, Catriona A. Macdonald, Kadmiel Maseyk, Kayla Mathes, Marguerite Mauritz, Melanie A. Mayes, Steve McNulty, Guofang Miao, Mirco Migliavacca, Scott Miller, Chelcy F. Miniat, Jennifer G. Nietz, Mats B. Nilsson, Asko Noormets, Hamidreza Norouzi, Christine S. O'Connell, Bruce Osborne, Cecilio Oyonarte, Zhuo Pang, Matthias Peichl, Elise Pendall, Jorge F. Perez‐Quezada, Claire L. Phillips, Richard P. Phillips, James W. Raich, Alexandre A. Renchon, Nadine K. Ruehr, Enrique P. Sánchez-Cañete, Matthew Saunders, Kathleen E. Savage, Marion Schrumpf, Russell L. Scott, Ulli Seibt, Whendee L. Silver, Wu Sun, Daphne Szutu, Kentaro Takagi, Masahiro Takagi, Munemasa Teramoto, Mark G. Tjoelker, Susan Trumbore, Masahito Ueyama, Rodrigo Vargas, Ruth K. Varner, Joseph Verfaillie, Christoph Vogel, Jinsong Wang, Greg Winston, Tana E. Wood, Juying Wu, Thomas Wutzler, Jiye Zeng, Tianshan Zha, Quan Zhang, Junliang ZouSourceGlobal Change BiologyYear2020
- Tungsten carbide (WC) nanostructures were prepared by carbothermal reduction (CR) of tungsten-impregnated pinewood-derived activated carbon (AC) at 1000 ◦C under an inert atmosphere. Brunauer–Emmet–Teller (BET) surface area, pore structures of the AC, and catalyst samples were evaluated by N2 adsorption–desorption experiments. The structures of the catalysts were characterized using X-ray powder diffraction (XRD). The morphologies and particle structures of the synthesized WC nanoparticles were investigated by field emission scanning electron microscopy (FESEM) and high-resolution transmiss...AuthorsQiangu Yan, Zhiyong CaiKeywordsSourceSustainable ChemistryYear2020
- AuthorsJohn SchelhasSourceRocky Mountain Mineral Law Foundation JournalYear2020
- Shales contain high levels of organic carbon (OC) and represent a large fraction of the Earth's reduced carbon stocks. While recent evidence suggests that shale‐derived OC may be actively cycled in riverine systems, this process is poorly understood and not currently considered in global C models. Through the use of sediment density fractionations, extractions, radiocarbon measurements, and chemical characterization, we provide information on the abundance, chemistry, and mobility of shale‐derived OC in floodplain sediments of a shale‐rich mountainous watershed. The heavy fraction of the...AuthorsPatricia M. Fox, Markus Bill, Katherine A. Heckman, Mark Conrad, Carolyn Anderson, Marco Keiluweit, Peter S. NicoKeywordsSourceJournal of Geophysical Research: BiogeosciencesYear2020
- Fire affects the quantity and quality of soil organic matter (SOM). While combustion of the O-horizon causes direct losses of SOM, fire also transforms the remaining SOM into a spectrum of thermally altered organic matter. Pyrogenic carbon (PyC) can resist degradation and may have important effects on soil carbon cycling. The objectives of this study are to examine the mobility of PyC. Studying the effects of wildfire is challenging due to the rapid post-fire changes in the ecosystem and lack of robust controls. We overcame those limitations by examining the Chimney Tops 2 Fire which...AuthorsLauren M. Matosziuk, Adrian Gallo, Jeff Hatten, Kevin D. Bladon, Danica Ruud, Maggie Bowman, Jessica Egan, Katherine A. Heckman, Michael SanClements, Brian Strahm, Tyler WeigleinKeywordsSourceFrontiers in Forests and Global ChangeYear2020
- AuthorsTimothy S. McCay, George Brown, Mac A. Callaham, Chih-Han Chang, Andrea Dávalos, Annise Dobson, Josef H. Görres, Bradley M. Herrick, Samuel W. James, Marie R. Johnston, Damhnait McHugh, Tanya Minteer, Jean-David Moore, Maryam Nouri-Aiin, Marta Novo, Jaime Ortiz-Pachar, Rebecca A. Pinder, Justin B. Richardson, Bruce A. Snyder, Katalin SzlaveczSourcePedobiologiaYear2020
- Forest inventorying is time-consuming and expensive. Recent research involving photogrammetry promises to reduce the cost of inventorying. Existing photogrammetry methods require substantial data-processing time, however. Our aim was to reduce data-acquisition and processing times while obtaining relatively accurate diameter estimates compared to manual and other digital measurements. We developed an algorithm to identify the ground and measure diameter at breast height (dbh) or any height along a stem from the recorded video footage of trees taken with a stereo camera. Footage acquisition...AuthorsNicholas Eliopoulos, Yezhi Shen, Minh Luong Nguyen, Vaastav Arora, Yuxin Zhang, Guofan Shao, Keith Woeste, Yung-Hsiang LuSourceJournal of ForestryYear2020
- Forest ecosystem services such as clean water, wildlife habitat, and timber supplies are increasingly threatened by drought and disturbances (e.g., harvesting, fires and conversion to other uses), which can have great impacts on stand development and water balance. Improved understanding of the hydrologic response of forested systems to drought and disturbance at spatiotemporal resolutions commensurate with these impacts is important for effective forest management. Evapotranspiration (ET) is a key hydrologic variable in assessing forest functioning and health, but it remains a challenge...AuthorsYun Yang, Martha Anderson, Feng Gao, Christopher Hain, Asko Noormets, Ge Sun, Randolph Wynne, Valerie Thomas, Liang SunKeywordsSourceRemote Sensing of EnvironmentYear2020
- Climate risk is a consequence of climate hazards, exposure, and the vulnerability (IPCC 2014). Here, we assess future (2040-2049) climate risk for the entire contiguous US at the county level with a novel climate risk index integrating multiple hazards, exposures and vulnerabilities. Future, weather and climate hazards are characterized as frequency of heat wave, cold spells, dryer, and heavy precipitation events along with anomalies of temperature and precipitation using high resolution (4 km) downscaled climate projections. Exposure is characterized by projections of population, infrastru...AuthorsBinita KC, J. M. Shepherd, Anthony W. King, Cassandra Johnson Gaither, Cassandra Johnson GaitherSourceNatural HazardsYear2020
- Latitudinal patterns of biodiversity have long been a central topic in ecology and evolutionary biology. However, while most previous studies have focused on native species, little effort has been devoted to latitudinal patterns of plant invasions (with a few exceptions based on data from sparse locations). Using the most up-to-date worldwide native and alien plant distribution data from 801 regions (including islands), we compared invasion levels (i.e. alien richness/total richness) in the Northern and Southern Hemispheres and across continental regions and islands around the globe....AuthorsQinfeng Guo, Brian S. Cade, Wayne Dawson, Franz Essl, Holger Kreft, Jan Pergl, Mark Kleunen, Patrick Weigelt, Marten Winter, Petr PysekKeywordsSourceJournal of BiogeographyYear2020