DOI: 10.1111/gcb.12614
论文题名: Ebullitive methane emissions from oxygenated wetland streams
作者: Crawford J.T. ; Stanley E.H. ; Spawn S.A. ; Finlay J.C. ; Loken L.C. ; Striegl R.G.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2014
卷: 20, 期: 11 起始页码: 3408
结束页码: 3422
语种: 英语
英文关键词: Carbon dioxide
; Ebullition
; Methane
; Rivers
; Upscaling
; Wetlands
Scopus关键词: ground water
; methane
; chemistry
; environmental monitoring
; river
; sediment
; time factor
; wetland
; Wisconsin
; Environmental Monitoring
; Geologic Sediments
; Groundwater
; Methane
; Rivers
; Time Factors
; Wetlands
; Wisconsin
英文摘要: Stream and river carbon dioxide emissions are an important component of the global carbon cycle. Methane emissions from streams could also contribute to regional or global greenhouse gas cycling, but there are relatively few data regarding stream and river methane emissions. Furthermore, the available data do not typically include the ebullitive (bubble-mediated) pathway, instead focusing on emission of dissolved methane by diffusion or convection. Here, we show the importance of ebullitive methane emissions from small streams in the regional greenhouse gas balance of a lake and wetland-dominated landscape in temperate North America and identify the origin of the methane emitted from these well-oxygenated streams. Stream methane flux densities from this landscape tended to exceed those of nearby wetland diffusive fluxes as well as average global wetland ebullitive fluxes. Total stream ebullitive methane flux at the regional scale (103 Mg C yr-1; over 6400 km2) was of the same magnitude as diffusive methane flux previously documented at the same scale. Organic-rich stream sediments had the highest rates of bubble release and higher enrichment of methane in bubbles, but glacial sand sediments also exhibited high bubble emissions relative to other studied environments. Our results from a database of groundwater chemistry support the hypothesis that methane in bubbles is produced in anoxic near-stream sediment porewaters, and not in deeper, oxygenated groundwaters. Methane interacts with other key elemental cycles such as nitrogen, oxygen, and sulfur, which has implications for ecosystem changes such as drought and increased nutrient loading. Our results support the contention that streams, particularly those draining wetland landscapes of the northern hemisphere, are an important component of the global methane cycle. © 2014 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62176
Appears in Collections: 影响、适应和脆弱性
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作者单位: U.S. Geological Survey, National Research Program, Boulder, CO, United States; Center for Limnology, University of Wisconsin-Madison, 680 N. Park St., Madison, WI, United States; St. Olaf College, Northfield, MN, United States; Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN, United States
Recommended Citation:
Crawford J.T.,Stanley E.H.,Spawn S.A.,et al. Ebullitive methane emissions from oxygenated wetland streams[J]. Global Change Biology,2014-01-01,20(11)