DOI: 10.1111/gcb.13205
论文题名: Warming alters coupled carbon and nutrient cycles in experimental streams
作者: Williamson T.J. ; Cross W.F. ; Benstead J.P. ; Gíslason G.M. ; Hood J.M. ; Huryn A.D. ; Johnson P.W. ; Welter J.R.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2016
卷: 22, 期: 6 起始页码: 2152
结束页码: 2164
语种: 英语
英文关键词: Benthic biofilms
; Climate change
; Coupled biogeochemical cycles
; Ecological stoichiometry
; Metabolism
; N2-fixation
; Nutrient uptake
; Temperature
Scopus关键词: benthic fauna
; biofilm
; carbon cycle
; climate change
; experimental study
; metabolism
; nitrogen fixation
; nutrient cycling
; nutrient uptake
; stoichiometry
; stream
; temperature effect
; algae
; Cyanobacteria
; Fungi
; carbon
; fresh water
; nitrogen
; phosphorus
; biofilm
; carbon cycle
; chemistry
; climate change
; ecosystem
; Iceland
; metabolism
; nitrogen cycle
; nitrogen fixation
; season
; temperature
; theoretical model
; Biofilms
; Carbon
; Carbon Cycle
; Climate Change
; Ecosystem
; Fresh Water
; Iceland
; Models, Theoretical
; Nitrogen
; Nitrogen Cycle
; Nitrogen Fixation
; Phosphorus
; Seasons
; Temperature
英文摘要: Although 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. © 2016 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/61379
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Ecology, Montana State University, Bozeman, MT, United States; Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, United States; Institute of Life and Environmental Sciences, University of Iceland, Askja, Sturlugata, 7, Reykjavík, Iceland; Department of Civil, Construction and Environmental Engineering, University of Alabama, Tuscaloosa, AL, United States; Department of Biology, St. Catherine University, Saint Paul, MN, United States; Department of Evolution, Ecology, and Organismal Biology, Aquatic Ecology Laboratory, The Ohio State University, Columbus, OH, United States
Recommended Citation:
Williamson T.J.,Cross W.F.,Benstead J.P.,et al. Warming alters coupled carbon and nutrient cycles in experimental streams[J]. Global Change Biology,2016-01-01,22(6)