DOI: 10.1007/s10533-015-0165-5
Scopus记录号: 2-s2.0-84951569783
论文题名: Geochemical drivers of organic matter decomposition in arctic tundra soils
作者: Herndon E.M. ; Yang Z. ; Bargar J. ; Janot N. ; Regier T.Z. ; Graham D.E. ; Wullschleger S.D. ; Gu B. ; Liang L.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2015
卷: 126, 期: 3 起始页码: 397
结束页码: 414
语种: 英语
英文关键词: Active layer
; Iron biogeochemistry
; Methane
; Soil organic matter
; Tundra soil
Scopus关键词: biogeochemistry
; carbon dioxide
; decomposition
; iron
; methane
; soil chemistry
; soil organic matter
; tundra soil
; Alaska
; Barrow
; United States
英文摘要: Climate change is warming tundra ecosystems in the Arctic, resulting in the decomposition of previously-frozen soil organic matter (SOM) and release of carbon (C) to the atmosphere; however, the processes that control SOM decomposition and C emissions remain highly uncertain. In this study, we evaluate geochemical factors that influence microbial production of carbon dioxide (CO2) and methane (CH4) in the seasonally-thawed active layer of interstitial polygonal tundra near Barrow, Alaska. We report spatial and seasonal patterns of dissolved gases in relation to the geochemical properties of Fe and organic C in soil and soil solution, as determined using spectroscopic and chromatographic techniques. The chemical composition of soil water collected during the annual thaw season varied significantly with depth. Soil water in the middle of the active layer contained abundant Fe(III), and aromatic-C and low-molecular-weight organic acids derived from SOM decomposition. At these depths, CH4 was positively correlated with the ratio of Fe(III) to total Fe in waterlogged transitional and low-centered polygons but negatively correlated in the drier flat- and high-centered polygons. These observations contradict the expectation that CH4 would be uniformly low where Fe(III) was high due to inhibition of methanogenesis by Fe(III)-reduction reactions. Our results suggest that vertically-stratified Fe redox reactions influence respiration/fermentation of SOM and production of substrates (e.g., low-molecular-weight organic acids) for methanogenesis, but that these effects vary with soil moisture. We infer that geochemical differences induced by water saturation dictate microbial products of SOM decomposition, and Fe geochemistry is an important factor regulating methanogenesis in anoxic tundra soils. © 2015, Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83441
Appears in Collections: 气候减缓与适应 气候变化事实与影响
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作者单位: Environmental Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, MS-6036, Oak Ridge, TN, United States; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, United States; Canadian Light Source, Saskatoon, SK, Canada; Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; Department of Geology, Kent State University, Kent, OH, United States; Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), UMR 7360 CNRS-Université de Lorraine, 15 Avenue du Charmois, Vandoeuvre, France
Recommended Citation:
Herndon E.M.,Yang Z.,Bargar J.,et al. Geochemical drivers of organic matter decomposition in arctic tundra soils[J]. Biogeochemistry,2015-01-01,126(3)