DOI: 10.1007/s10533-014-0005-z
Scopus记录号: 2-s2.0-84904822798
论文题名: Stable isotopes track biogeochemical processes under seasonal ice cover in a shallow, productive lake
作者: Gammons C.H. ; Henne W. ; Poulson S.R. ; Parker S.R. ; Johnston T.B. ; Dore J.E. ; Boyd E.S.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 120, 期: 2018-01-03 起始页码: 359
结束页码: 379
语种: 英语
英文关键词: Eutrophication
; Geochemistry
; Lake stratification
; Methanogenesis
; Photosynthesis
; Respiration
Scopus关键词: Salmonidae
英文摘要: Biogeochemical dynamics under seasonal ice cover were investigated in the shallow (<10 m) water column of highly productive Georgetown Lake, western Montana, USA. This high altitude (1,800 m) reservoir is well-mixed in summer, but becomes strongly stratified under ice cover (mid-November-mid-May). A rapid drop in dissolved oxygen (DO) concentration and rise in dissolved inorganic carbon (DIC) concentration was observed after the onset of ice, with a corresponding increase in δ18O-DO and decrease in δ13C-DIC, likely caused by respiration (R) of organic carbon. Photosynthesis/respiration ratios (P/R) estimated from simultaneous measurement of DO and δ18O-DO were near unity prior to ice formation but then systematically decreased with time and depth in the lake under ice cover. P/R in the water column was higher at a shallower monitoring site compared to a deeper site near the dam outlet, which may have been important for over-winter survival of salmonids. By March, the bottom 3 m of the water column at both sites was anoxic, with the bottom 1 m being euxinic. Elevated concentrations of dissolved sulfide, ammonium, phosphate, Fe2+, and Mn2+ in deep water suggest coupling of organic carbon degradation with reduction of a number of electron acceptors (e.g., Fe3+, NO3-, SO42-). The concentrations and δ34S values of H2S in the deep water and SO42- in the shallow water were similar, indicating near-complete reduction of sulfate in the euxinic zone. Late in the winter, an influx of isotopically heavy DIC was noted in the deep water coincident with a buildup of dissolved CH4 to concentrations >1 mM. These trends are attributed to acetoclastic methanogenesis in the benthic sediments. This pool of dissolved CH4 was likely released from the lake to the atmosphere during spring ice-off and lake turnover. © 2014 Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83650
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: Department of Geological Engineering, Montana Tech of The University of Montana, Butte, MT, 59701, United States; Department of Geological Sciences and Engineering, University of Nevada-Reno, Reno, NV, 89557, United States; Department of Chemistry and Geochemistry, Montana Tech of The University of Montana, Butte, MT, 59701, United States; Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, United States; Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States; Pioneer Technical Services, Inc., Butte, MT, 59701, United States
Recommended Citation:
Gammons C.H.,Henne W.,Poulson S.R.,et al. Stable isotopes track biogeochemical processes under seasonal ice cover in a shallow, productive lake[J]. Biogeochemistry,2014-01-01,120(2018-01-03)