Show simple item record

dc.contributor.authorWilliamson, Tanner J
dc.contributor.authorCross, Wyatt F.
dc.contributor.authorBenstead, Jonathan P
dc.contributor.authorGislason, Gisli M
dc.contributor.authorHood, James M.
dc.contributor.authorHuryn, Alexander D.
dc.contributor.authorJohnson, Philip W
dc.contributor.authorWelter, Jill R
dc.identifier.citationWilliamson, Tanner J., Wyatt F. Cross, Jonathan P. Benstead, Gisli M. Gislason, James M. Hood, Alexander D. Huryn, Philip W. Johnson, and Jill R. Welter. "Warming alters coupled carbon and nutrient cycles in experimental streams.." Global Change Biology 22, no. 6 (June 2016): 2152-2164. DOI:
dc.description.abstractAlthough much effort has been devoted to quantifying how warming alters carbon cycling across diverse ecosystems, less is known about how these changes are linked to the cycling of bioavailable nitrogen and phosphorus. In freshwater ecosystems, benthic biofilms (i.e. thin films of algae, bacteria, fungi, and detrital matter) act as biogeochemical hotspots by controlling important fluxes of energy and material. Understanding how biofilms respond to warming is thus critical for predicting responses of coupled elemental cycles in freshwater systems. We developed biofilm communities in experimental streamside channels along a gradient of mean water temperatures (7.5–23.6 °C), while closely maintaining natural diel and seasonal temperature variation with a common water and propagule source. Both structural (i.e. biomass, stoichiometry, assemblage structure) and functional (i.e. metabolism, N2-fixation, nutrient uptake) attributes of biofilms were measured on multiple dates to link changes in carbon flow explicitly to the dynamics of nitrogen and phosphorus. Temperature had strong positive effects on biofilm biomass (2.8- to 24-fold variation) and net ecosystem productivity (44- to 317-fold variation), despite extremely low concentrations of limiting dissolved nitrogen. Temperature had surprisingly minimal effects on biofilm stoichiometry: carbon:nitrogen (C:N) ratios were temperature-invariant, while carbon:phosphorus (C:P) ratios declined slightly with increasing temperature. Biofilm communities were dominated by cyanobacteria at all temperatures (>91% of total biovolume) and N2-fixation rates increased up to 120-fold between the coldest and warmest treatments. Although ammonium-N uptake increased with temperature (2.8- to 6.8-fold variation), the much higher N2-fixation rates supplied the majority of N to the ecosystem at higher temperatures. Our results demonstrate that temperature can alter how carbon is cycled and coupled to nitrogen and phosphorus. The uncoupling of C fixation from dissolved inorganic nitrogen supply produced large unexpected changes in biofilm development, elemental cycling, and likely downstream exports of nutrients and organic matter.en_US
dc.description.sponsorshipNational Science Foundation (DEB-0949774 and DEB-0949726); Montana Institute on Ecosystems; St. Catherine University; Icelandic Research Fund (i. Rannsóknasjóður) 141840-051en_US
dc.rightsPublisher source must be acknowledged with citation Must link to publisher version with set statement (see policy)en_US
dc.subjectbenthic biofilmsen_US
dc.subjectclimate changeen_US
dc.subjectcoupled biogeochemical cyclesen_US
dc.subjectecological stoichiometryen_US
dc.subjectnutrient uptakeen_US
dc.titleWarming alters coupled carbon and nutrient cycles in experimental streams.en_US
mus.citation.journaltitleGlobal Change Biologyen_US
mus.identifier.categoryLife Sciences & Earth Sciencesen_US
mus.relation.collegeCollege of Letters & Scienceen_US
mus.relation.universityMontana State University - Bozemanen_US

Files in this item


This item appears in the following Collection(s)

Show simple item record

MSU uses DSpace software, copyright © 2002-2017  Duraspace. For library collections that are not accessible, we are committed to providing reasonable accommodations and timely access to users with disabilities. For assistance, please submit an accessibility request for library material.