DOI: 10.1002/2017JG004090
Scopus记录号: 2-s2.0-85045521436
论文题名: Influence of Hydrological Perturbations and Riverbed Sediment Characteristics on Hyporheic Zone Respiration of CO2 and N2
作者: Newcomer M.E. ; Hubbard S.S. ; Fleckenstein J.H. ; Maier U. ; Schmidt C. ; Thullner M. ; Ulrich C. ; Flipo N. ; Rubin Y.
刊名: Journal of Geophysical Research: Biogeosciences
ISSN: 21698953
出版年: 2018
卷: 123, 期: 3 起始页码: 902
结束页码: 922
语种: 英语
英文关键词: dynamic permeability
; hyporheic biogenic gas
; losing rivers
; Mediterranean climate
; nutrient dynamics
; water table fluctuations
Scopus关键词: anoxic conditions
; aquifer
; carbon cycle
; carbon dioxide
; denitrification
; dissolved gas
; dissolved organic carbon
; hydrobiology
; hyporheic zone
; Mediterranean environment
; nitrogen cycle
; nutrient dynamics
; respiration
; river water
; seepage
英文摘要: Rivers in climatic zones characterized by dry and wet seasons often experience periodic transitions between losing and gaining conditions across the river-aquifer continuum. Infiltration shifts can stimulate hyporheic microbial biomass growth and cycling of riverine carbon and nitrogen leading to major exports of biogenic CO2 and N2 to rivers. In this study, we develop and test a numerical model that simulates biological-physical feedback in the hyporheic zone. We used the model to explore different initial conditions in terms of dissolved organic carbon availability, sediment characteristics, and stochastic variability in aerobic and anaerobic conditions from water table fluctuations. Our results show that while highly losing rivers have greater hyporheic CO2 and N2 production, gaining rivers allowed the greatest fraction of CO2 and N2 production to return to the river. Hyporheic aerobic respiration and denitrification contributed 0.1–2 g/m2/d of CO2 and 0.01–0.2 g/m2/d of N2; however, the suite of potential microbial behaviors varied greatly among sediment characteristics. We found that losing rivers that consistently lacked an exit pathway can store up to 100% of the entering C/N as subsurface biomass and dissolved gas. Our results demonstrate the importance of subsurface feedbacks whereby microbes and hydrology jointly control fate of C and N and are strongly linked to wet-season control of initial sediment conditions and hydrologic control of seepage direction. These results provide a new understanding of hydrobiological and sediment-based controls on hyporheic zone respiration, including a new explanation for the occurrence of anoxic microzones and large denitrification rates in gravelly riverbeds. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114332
Appears in Collections: 气候减缓与适应
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作者单位: Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States; Department of Hydrogeology, Helmholtz-Centre for Environmental Research, UFZ, Leipzig, Germany; Department of Applied Geology, Geoscience Centre of the University of Göttingen, Göttingen, Germany; Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research, UFZ, Leipzig, Germany; Geosciences Department, MINES ParisTech, PSL Research University, Paris, France; Department of Civil and Environmental Engineering, University of California, Berkeley, CA, United States
Recommended Citation:
Newcomer M.E.,Hubbard S.S.,Fleckenstein J.H.,et al. Influence of Hydrological Perturbations and Riverbed Sediment Characteristics on Hyporheic Zone Respiration of CO2 and N2[J]. Journal of Geophysical Research: Biogeosciences,2018-01-01,123(3)