Now showing items 187-206 of 265

  • Quantifying the production of dissolved organic nitrogen in headwater streams using 15N tracer additions 

    Johnson, Laura T.; Tank, Jennifer L.; Hall, Robert O.; Mulholland, Patrick J.; Hamilton, Stephen K.; Valett, H. Maurice; Webster, Jackson R.; Bernot, Melody J.; McDowell, William H.; Peterson, Bruce J.; Thomas, Suzanne M. (Association for the Sciences of Limnology and Oceanography, 2013-07)
    Most nitrogen (N) assimilation in lake and marine ecosystems is often subsequently released via autochthonous dissolved organic nitrogen (DON) production, but autochthonous DON production has yet to be quantified in flowing ...
  • Rapid screening for freshwater bacterial groups by using reverse line blot hybridization 

    Zwart, Gabriel; van Hannen, Erik J.; Kamst-van Agterveld, Miranda P.; Van der Gucht, Katleen; Lindstrom, Eva S.; Van Wichelen, Jeroen; Lauridsen, Torben; Crump, Byron C.; Han, Suk-Kyun; Declerck, Steven (American Society for Microbiology, 2003-10)
    The identification of phylogenetic clusters of bacteria that are common in freshwater has provided a basis for probe design to target important freshwater groups. We present a set of 16S ribosomal RNA gene-based oligonucleotide ...
  • Recent changes in nitrate and dissolved organic carbon export from the upper Kuparuk River, North Slope, Alaska 

    McClelland, James W.; Stieglitz, Marc; Pan, Feifei; Holmes, Robert M.; Peterson, Bruce J. (American Geophysical Union, 2007-11-08)
    Export of nitrate and dissolved organic carbon (DOC) from the upper Kuparuk River between the late 1970s and early 2000s was evaluated using long-term ecological research (LTER) data in combination with solute flux and ...
  • Reconciling carbon-cycle concepts, terminology, and methods 

    Chapin, F. Stuart; Woodwell, G. M.; Randerson, James T.; Rastetter, Edward B.; Lovett, G. M.; Baldocchi, Dennis D.; Clark, D. A.; Harmon, Mark E.; Schimel, David S.; Valentini, R.; Wirth, C.; Aber, J. D.; Cole, Jonathan J.; Goulden, Michael L.; Harden, J. W.; Heimann, M.; Howarth, Robert W.; Matson, P. A.; McGuire, A. David; Melillo, Jerry M.; Mooney, H. A.; Neff, Jason C.; Houghton, Richard A.; Pace, Michael L.; Ryan, M. G.; Running, Steven W.; Sala, Osvaldo E.; Schlesinger, William H.; Schulze, E.-D. (2006-01-06)
    Recent patterns and projections of climatic change have focused increased scientific and public attention on patterns of carbon (C) cycling and its controls, particularly the factors that determine whether an ecosystem is ...
  • Recovery from disturbance requires resynchronization of ecosystem nutrient cycles 

    Rastetter, Edward B.; Yanai, Ruth D.; Thomas, R. Q.; Vadeboncoeur, M. A.; Fahey, Timothy J.; Fisk, M. C.; Kwiatkowski, Bonnie L.; Hamburg, S. P. (Ecological Society of America, 2013-04)
    Nitrogen (N) and phosphorus (P) are tightly cycled in most terrestrial ecosystems, with plant uptake more than 10 times higher than the rate of supply from deposition and weathering. This near-total dependence on recycled ...
  • The regional and global significance of nitrogen removal in lakes and reservoirs 

    Harrison, John A.; Maranger, Roxane J.; Alexander, Richard B.; Giblin, Anne E.; Jacinthe, Pierre-Andre; Mayorga, Emilio; Seitzinger, Sybil P.; Sobota, Daniel J.; Wollheim, Wilfred M. (2008-06-25)
    Human activities have greatly increased the transport of biologically available N through watersheds to potentially sensitive coastal ecosystems. Lentic water bodies (lakes and reservoirs) have the potential to act as ...
  • Regional differences in phosphorus budgets in intensive soybean agriculture 

    Riskin, Shelby H.; Porder, Stephen; Schipanski, Meagan E.; Bennett, Elena M.; Neill, Christopher (University of California Press, 2013-01)
    Fertilizer-intensive agriculture has been integral to increasing food production over the past half century but has been accompanied by environmental costs. We use case studies of phosphorus fertilizer use in the world’s ...
  • Regional-scale phenology modeling based on meteorological records and remote sensing observations 

    Yang, Xi; Mustard, John F.; Tang, Jianwu; Hong, Xu (American Geophysical Union, 2012-09-14)
    Changes of vegetation phenology in response to climate change in the temperate forests have been well documented recently and have important implications on the regional and global carbon and water cycles. Predicting the ...
  • Relationship between river size and nutrient removal 

    Wollheim, Wilfred M.; Vorosmarty, Charles J.; Peterson, Bruce J.; Seitzinger, Sybil P.; Hopkinson, Charles S. (American Geophysical Union, 2006-03-30)
    We present a conceptual approach for evaluating the biological and hydrological controls of nutrient removal in different sized rivers within an entire river network. We emphasize a per unit area biological parameter, the ...
  • Release of multiple bubbles from cohesive sediments 

    Algar, Christopher K.; Boudreau, Bernard P.; Barry, Mark A. (American Geophysical Union, 2011-04-20)
    Methane is a strong greenhouse gas, and marine and wetland sediments constitute significant sources to the atmosphere. This flux is dominated by the release of bubbles, and quantitative prediction of this bubble flux has ...
  • Residence time distributions in surface transient storage zones in streams : estimation via signal deconvolution 

    Gooseff, Michael N.; Benson, David A.; Briggs, Martin A.; Weaver, Mitchell; Wollheim, Wilfred M.; Peterson, Bruce J.; Hopkinson, Charles S. (American Geophysical Union, 2011-05-11)
    Little is known about the impact of surface transient storage (STS) zones on reach-scale transport and the fate of dissolved nutrients in streams. Exchange with these locations may influence the rates of nutrient cycling ...
  • Response of a summertime Antarctic marine ­bacterial community to glucose and ammonium enrichment 

    Ducklow, Hugh W.; Myers, Kristen M. S.; Erickson, Matthew; Ghiglione, Jean-Francois; Murray, Alison E. (Inter-Research, 2011-09-20)
    Along the western Antarctic Peninsula, marine bacterioplankton respond to the spring phytoplankton bloom with increases in abundance, production and growth rates, and a seasonal succession in bacterial community composition ...
  • The response of Arctic vegetation and soils following an unusually severe tundra fire 

    Bret-Harte, M. Syndonia; Mack, Michelle C.; Shaver, Gaius R.; Huebner, Diane C.; Johnston, Miriam; Mojica, Camilo A.; Pizano, Camila; Reiskind, Julia A. (The Royal Society, 2013-07-08)
    Fire causes dramatic short-term changes in vegetation and ecosystem function, and may promote rapid vegetation change by creating recruitment opportunities. Climate warming likely will increase the frequency of wildfire ...
  • Response of benthic metabolism and nutrient cycling to reductions in wastewater loading to Boston Harbor, USA 

    Tucker, Jane; Giblin, Anne E.; Hopkinson, Charles S.; Kelsey, Samuel W.; Howes, Brian L. (Elsevier, 2014-10-02)
    We describe the long-term response of benthic metabolism in depositional sediments of Boston Harbor, MA, to large reductions in organic matter and nutrient loading. Although Boston Harbor received very high loadings of ...
  • Response of dark respiration to temperature in Eriophorum vaginatum from a 30-year-old transplant experiment in Alaska 

    van de Weg, Martine J.; Fetcher, Ned; Shaver, Gaius R. (2012-09)
    Background: In the Arctic region, temperature increases are expected to be greater under anticipated climate change than the global average. Understanding how dark respiration (Rd) of common Arctic plant species acclimates ...
  • The response of nematodes to deep-sea CO2 sequestration : a quantile regression approach 

    Fleeger, John W.; Johnson, David S.; Carman, K. R.; Weisenhorn, P. B.; Gabriele, A.; Thistle, D.; Barry, James P. (2010-01)
    One proposed approach to ameliorate the effects of global warming is sequestration of the greenhouse gas CO2 in the deep sea. To evaluate the environmental impact of this approach, we exposed the sediment-dwelling fauna ...
  • Response of the benthic food web to short- and long-term nutrient 1 enrichment in saltmarsh mudflats 

    Pascal, Pierre-Yves; Fleeger, John W.; Boschker, Henricus T. S.; Mitwally, Hanan M.; Johnson, David S. (2013-01)
    We examined the responses of biota at or near the base of the benthic food web to nutrient enrichment in salt marsh mudflats in Plum Island estuary (Massachusetts, USA). To simulate eutrophication, nitrate and phosphate ...
  • Responses of a tundra system to warming using SCAMPS : a stoichiometrically coupled, acclimating microbe–plant–soil model 

    Sistla, Seeta A.; Rastetter, Edward B.; Schimel, Joshua P. (Ecological Society of America, 2014-02)
    Soils, plants, and microbial communities respond to global change perturbations through coupled, nonlinear interactions. Dynamic ecological responses complicate projecting how global change disturbances will influence ...
  • Responses of soil carbon, nitrogen and cations to the frequency and seasonality of prescribed burning in a Cape Cod oak-pine forest 

    Neill, Christopher; Patterson, William A.; Crary, David W. (2007-05-09)
    Fire is an important component of the historic disturbance regime of oak and pine forests that occupy sandy soils of the coastal outwash plain of the northeastern U.S. Today prescribed fire is used for fuel reduction and ...
  • Rhizosphere heterogeneity shapes abundance and activity of sulfur-oxidizing bacteria in vegetated salt marsh sediments 

    Thomas, Francois; Giblin, Anne E.; Cardon, Zoe G.; Sievert, Stefan M. (Frontiers Media, 2014-06-23)
    Salt marshes are highly productive ecosystems hosting an intense sulfur (S) cycle, yet little is known about S-oxidizing microorganisms in these ecosystems. Here, we studied the diversity and transcriptional activity of ...