DOI: 10.1111/gcb.12182
论文题名: Climate change reduces the net sink of CH4 and N2O in a semiarid grassland
作者: Dijkstra F.A. ; Morgan J.A. ; Follett R.F. ; Lecain D.R.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2013
卷: 19, 期: 6 起始页码: 1816
结束页码: 1826
语种: 英语
英文关键词: Climate change
; Global warming potential
; Multifactor experiment
; PHACE
; Positive feedback
; Water availability
Scopus关键词: methane
; nitrogen oxide
; carbon dioxide
; climate change
; global warming
; grassland
; greenhouse gas
; methane
; nitrous oxide
; semiarid region
; soil moisture
; water availability
; article
; climate change
; ecosystem
; metabolism
; Poaceae
; Climate Change
; Ecosystem
; Methane
; Nitrogen Oxides
; Poaceae
英文摘要: Atmospheric concentrations of methane (CH4) and nitrous oxide (N2O) have increased over the last 150 years because of human activity. Soils are important sources and sinks of both potent greenhouse gases where their production and consumption are largely regulated by biological processes. Climate change could alter these processes thereby affecting both rate and direction of their exchange with the atmosphere. We examined how a rise in atmospheric CO2 and temperature affected CH4 and N2O fluxes in a well-drained upland soil (volumetric water content ranging between 6% and 23%) in a semiarid grassland during five growing seasons. We hypothesized that responses of CH4 and N2O fluxes to elevated CO2 and warming would be driven primarily by treatment effects on soil moisture. Previously we showed that elevated CO2 increased and warming decreased soil moisture in this grassland. We therefore expected that elevated CO2 and warming would have opposing effects on CH4 and N2O fluxes. Methane was taken up throughout the growing season in all 5 years. A bell-shaped relationship was observed with soil moisture with highest CH4 uptake at intermediate soil moisture. Both N2O emission and uptake occurred at our site with some years showing cumulative N2O emission and other years showing cumulative N2O uptake. Nitrous oxide exchange switched from net uptake to net emission with increasing soil moisture. In contrast to our hypothesis, both elevated CO2 and warming reduced the sink of CH4 and N2O expressed in CO2 equivalents (across 5 years by 7% and 11% for elevated CO2 and warming respectively) suggesting that soil moisture changes were not solely responsible for this reduction. We conclude that in a future climate this semiarid grassland may become a smaller sink for atmospheric CH4 and N2O expressed in CO2-equivalents. © 2013 Blackwell Publishing Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62438
Appears in Collections: 影响、适应和脆弱性
There are no files associated with this item.
作者单位: Department of Environmental Sciences and Centre for Carbon, Water and Food, Faculty of Agriculture and Environment, The University of Sydney, Camden, NSW, 2570, Australia; Rangeland Resources Research Unit, USDA-ARS, Fort Collins, CO, 80526, United States; Soil, Plant, and Nutrient Research Unit, USDA-ARS, Fort Collins, CO, 80526, United States
Recommended Citation:
Dijkstra F.A.,Morgan J.A.,Follett R.F.,et al. Climate change reduces the net sink of CH4 and N2O in a semiarid grassland[J]. Global Change Biology,2013-01-01,19(6)