Now showing items 259-278 of 281

    • The terrestrial biosphere as a net source of greenhouse gases to the atmosphere 

      Tian, Hanqin; Lu, Chaoqun; Ciais, Philippe; Michalak, Anna M.; Canadell, Josep G.; Saikawa, Eri; Huntzinger, Deborah N.; Gurney, Kevin R.; Sitch, Stephen; Zhang, Bowen; Yang, Jia; Bousquet, Philippe; Bruhwiler, Lori; Chen, Guangsheng; Dlugokencky, Edward J.; Friedlingstein, Pierre; Melillo, Jerry M.; Pan, Shufen; Poulter, Benjamin; Prinn, Ronald G.; Saunois, Marielle; Schwalm, Christopher R.; Wofsy, Steven C. (2015-12-21)
      The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) and therefore plays an important role in regulating atmospheric composition and climate1. ...
    • Terrestrial C sequestration at elevated CO2 and temperature : the role of dissolved organic N loss 

      Rastetter, Edward B.; Perakis, Steven S.; Shaver, Gaius R.; Agren, Goran I. (2004-06-07)
      We used a simple model of carbon–nitrogen (C–N) interactions in terrestrial ecosystems to examine the responses to elevated CO2 and to elevated CO2 plus warming in ecosystems that had the same total nitrogen loss but that ...
    • Testing isosource : stable isotope analysis of a tropical fishery with diverse organic matter sources 

      Benstead, Jonathan P.; March, James G.; Fry, Brian; Ewel, Katherine C.; Pringle, Catherine M. (Ecological Society of America, 2006-02)
      We sampled consumers and organic matter sources (mangrove litter, freshwater swamp-forest litter, seagrasses, seagrass epiphytes, and marine particulate organic matter [MPOM]) from four estuaries on Kosrae, Federated States ...
    • Thermal adaptation of soil microbial respiration to elevated temperature 

      Bradford, Mark A.; Davies, Christian A.; Frey, Serita D.; Maddox, Thomas R.; Melillo, Jerry M.; Mohan, Jacqueline E.; Reynolds, James F.; Treseder, Kathleen K.; Wallenstein, Matthew D. (2008-07-22)
      In the short-term heterotrophic soil respiration is strongly and positively related to temperature. In the long-term its response to temperature is uncertain. One reason for this is because in field experiments increases ...
    • Thinking outside the channel : modeling nitrogen cycling in networked river ecosystems 

      Helton, Ashley M.; Poole, Geoffrey C.; Meyer, Judy L.; Wollheim, Wilfred M.; Peterson, Bruce J.; Mulholland, Patrick J.; Bernhardt, Emily S.; Stanford, Jack A.; Arango, Clay P.; Ashkenas, Linda R.; Cooper, Lee W.; Dodds, Walter K.; Gregory, Stanley V.; Hall, Robert O.; Hamilton, Stephen K.; Johnson, Sherri L.; McDowell, William H.; Potter, Jody D.; Tank, Jennifer L.; Thomas, Suzanne M.; Valett, H. Maurice; Webster, Jackson R.; Zeglin, Lydia (Ecological Society of America, 2010-09-08)
      Agricultural and urban development alters nitrogen and other biogeochemical cycles in rivers worldwide. Because such biogeochemical processes cannot be measured empirically across whole river networks, simulation models ...
    • Tight coupling between leaf area index and foliage N content in arctic plant communities 

      van Wijk, Mark T.; Williams, Mathew; Shaver, Gaius R. (2004-09-17)
      The large spatial heterogeneity of arctic landscapes complicates efforts to quantify key processes of these ecosystems, for example productivity, at the landscape level. Robust relationships that help to simplify and ...
    • Tools for the microbiome : nano and beyond 

      Biteen, Julie S.; Blainey, Paul C.; Cardon, Zoe G.; Chun, Miyoung; Church, George M.; Dorrestein, Pieter C.; Fraser, Scott E.; Gilbert, Jack A.; Jansson, Janet K.; Knight, Rob; Miller, Jeff F.; Ozcan, Aydogan; Prather, Kimberly A.; Quake, Stephen R.; Ruby, Edward G.; Silver, Pamela A.; Taha, Sharif; van den Engh, Ger; Weiss, Paul S.; Wong, Gerard C. L.; Wright, Aaron T.; Young, Thomas D. (American Chemical Society, 2015-12-22)
      The microbiome presents great opportunities for understanding and improving the world around us and elucidating the interactions that compose it. The microbiome also poses tremendous challenges for mapping and manipulating ...
    • Top-down and bottom-up control of infauna varies across the saltmarsh landscape 

      Fleeger, John W.; Johnson, David S.; Galvan, Kari A.; Deegan, Linda A. (2007-12)
      Responses of infaunal saltmarsh benthic invertebrates to whole-ecosystem fertilization and predator removal were quantified in Plum Island Estuary, Massachusetts, USA. Throughout a growing season, we enriched an experimental ...
    • Total and phytoplankton mediated bottom-up control of bacterioplankton change with temperature in NE Atlantic shelf waters 

      Moran, Xose Anxelu G.; Calvo-Diaz, Alejandra; Ducklow, Hugh W. (Inter-Research, 2010-01-20)
      The regulation of heterotrophic bacterial growth by resource supply (bottom-up control) was temperature-dependent in our analysis of data obtained during 2006 in the euphotic layer of the southern Bay of Biscay (NE Atlantic) ...
    • Towards a better understanding of microbial carbon flux in the sea 

      Gasol, Josep M.; Pinhassi, Jarone; Alonso-Saez, Laura; Ducklow, Hugh W.; Herndl, Gerhard J.; Koblizek, Michal; Labrenz, Matthias; Luo, Ya-Wei; Moran, Xose Anxelu G.; Reinthaler, Thomas; Simon, Meinhard (Inter-Research, 2008-09-18)
      We now have a relatively good idea of how bulk microbial processes shape the cycling of organic matter and nutrients in the sea. The advent of the molecular biology era in microbial ecology has resulted in advanced knowledge ...
    • Trajectory shifts in the Arctic and Subarctic freshwater cycle 

      Peterson, Bruce J.; McClelland, James W.; Curry, Ruth G.; Holmes, Robert M.; Walsh, John E.; Aagaard, Knut (2006-06-22)
      Manifold changes in the freshwater cycle of high-latitude lands and oceans have been reported in the past few years. A synthesis of these changes in sources of freshwater and in ocean freshwater storage illustrates the ...
    • Trophic structure of benthic communities in the Cabo Frio upwelling system (southeastern Brazilian shelf) : a temporal study using stable isotope analysis 

      Corbisier, Thais N.; Petti, Monica A. V.; Soares, Lucy S. H.; Muto, Elizabeti Y.; Bromberg, Sandra; Valiela, Ivan (Inter-Research, 2014-10-09)
      In Brazil, coastal upwelling is observed in 7 areas along the southeastern/southern region and is most pronounced near Cabo Frio, Rio de Janeiro. This region is exposed to moderate seasonal Ekman-driven upwelling that ...
    • Turnover rates of nitrogen stable isotopes in the salt marsh mummichog, Fundulus heteroclitus, following a laboratory diet switch 

      Logan, John; Haas, Heather; Deegan, Linda A.; Gaines, Emily F. (2005-09-19)
      Nitrogen stable isotopes are frequently used in ecological studies to estimate trophic position and determine movement patterns. Knowledge of tissue-specific turnover and nitrogen discrimination for the study organisms is ...
    • Ultrahigh bacterial production in a eutrophic subtropical Australian river : does viral lysis short-circuit the microbial loop? 

      Pollard, Peter C.; Ducklow, Hugh W. (Association for the Sciences of Limnology and Oceanography, 2011-05)
      We studied trophic dynamics in a warm eutrophic subtropical river (Bremer River, Australia) to determine potential sources of dissolved organic carbon (DOC) and the fate of heterotrophic bacterial production. Sustained ...
    • Uncertainty analysis of vegetation distribution in the northern high latitudes during the 21st century with a dynamic vegetation model 

      Jiang, Yueyang; Zhuang, Qianlai; Schaphoff, Sibyll; Sitch, Stephen; Sokolov, Andrei P.; Kicklighter, David W.; Melillo, Jerry M. (John Wiley & Sons, 2012-02-13)
      This study aims to assess how high-latitude vegetation may respond under various climate scenarios during the 21st century with a focus on analyzing model parameters induced uncertainty and how this uncertainty compares ...
    • Use of non-natal estuaries by migratory striped bass (Morone saxatilis) in summer 

      Mather, Martha E.; Finn, John T.; Ferry, Kristen H.; Deegan, Linda A.; Nelson, Gary A. (U.S. Dept. of Commerce, NOAA NMFS, 2009-07)
      For most migratory fish, little is known about the location and size of foraging areas or how long individuals remain in foraging areas, even though these attributes may affect their growth, survival, and impact on ...
    • Using indirect methods to constrain symbiotic nitrogen fixation rates : a case study from an Amazonian rain forest 

      Cleveland, Cory C.; Houlton, Benjamin Z.; Neill, Christopher; Reed, Sasha C.; Townsend, Alan R.; Wang, Yingping (Springer, 2009-12-05)
      Human activities have profoundly altered the global nitrogen (N) cycle. Increases in anthropogenic N have had multiple effects on the atmosphere, on terrestrial, freshwater and marine ecosystems, and even on human health. ...
    • Variability in the carbon isotopic composition of foliage carbon pools (soluble carbohydrates, waxes) and respiration fluxes in southeastern U.S. pine forests 

      Mortazavi, Behzad; Conte, Maureen H.; Chanton, Jeffrey P.; Weber, John C.; Martin, Timothy A.; Cropper, Wendell P. (American Geophysical Union, 2012-04-19)
      We measured the δ13C of assimilated carbon (foliage organic matter (δCOM), soluble carbohydrates (δCSC), and waxes (δCW)) and respiratory carbon (foliage (δCFR), soil (δCSR) and ecosystem 13CO2 (δCER)) for two years at ...
    • Vegetation shifts observed in arctic tundra 1.5 decades after fire 

      Barrett, Kirsten; Rocha, Adrian V.; van de Weg, Martine J.; Shaver, Gaius R. (2012-01-27)
      With anticipated climate change, tundra fires are expected to occur more frequently in the future, but data on the longer term effects of fire on tundra vegetation composition are scarce. This study therefore addresses ...
    • Western Maine Coastal Current reduces primary production rates, zooplankton abundance and benthic nutrient fluxes in Massachusetts Bay 

      McManus, M. Conor; Oviatt, Candace A.; Giblin, Anne E.; Tucker, Jane; Turner, Jefferson T. (2013-08)
      Primary production was measured from 1992-2010 in Massachusetts Bay and just outside Boston Harbor for the Massachusetts Water Resources Authority’s outfall monitoring program. In 2003, annual primary production decreased ...