DOI: 10.1007/s10533-015-0139-7
Scopus记录号: 2-s2.0-84943661409
论文题名: Hot spots for carbon emissions from Mediterranean fluvial networks during summer drought
作者: Gómez-Gener L. ; Obrador B. ; von Schiller D. ; Marcé R. ; Casas-Ruiz J.P. ; Proia L. ; Acuña V. ; Catalán N. ; Muñoz I. ; Koschorreck M.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2015
卷: 125, 期: 3 起始页码: 409
结束页码: 426
语种: 英语
英文关键词: Carbon dioxide
; Fluvial network
; Greenhouse gas fluxes
; Methane
; Summer drought
; Temporary rivers
Scopus关键词: biogeochemistry
; carbon dioxide
; carbon emission
; concentration (composition)
; drought
; ephemeral pool
; fluvial process
; gas exchange
; global change
; greenhouse gas
; heuristics
; impoundment
; Mediterranean environment
; methane
; river system
; spatiotemporal analysis
; summer
英文摘要: During summer drought, Mediterranean fluvial networks are transformed into highly heterogeneous landscapes characterized by different environments (i.e., running and impounded waters, isolated river pools and dry beds). This hydrological setting defines novel biogeochemically active areas that could potentially increase the rates of carbon emissions from the fluvial network to the atmosphere. Using chamber methods, we aimed to identify hot spots for carbon dioxide (CO2) and methane (CH4) emissions from two typical Mediterranean fluvial networks during summer drought. The CO2 efflux from dry beds (mean ± SE = 209 ± 10 mmol CO2 m−2 d−1) was comparable to that from running waters (120 ± 33 mmol m−2 d−1) and significantly higher than from impounded waters (36.6 ± 8.5 mmol m−2 d−1) and isolated pools (17.2 ± 0.9 mmol m−2 d−1). In contrast, the CH4 efflux did not significantly differ among environments, although the CH4 efflux was notable in some impounded waters (13.9 ± 10.1 mmol CH4 m−2 d−1) and almost negligible in the remaining environments (mean <0.3 mmol m−2 d−1). Diffusion was the only mechanism driving CO2 efflux in all environments and was most likely responsible for CH4 efflux in running waters, isolated pools and dry beds. In contrast, the CH4 efflux in impounded waters was primarily ebullition-based. Using a simple heuristic approach to simulate potential changes in carbon emissions from Mediterranean fluvial networks under future hydrological scenarios, we show that an extreme drying out (i.e., a four-fold increase of the surface area of dry beds) would double the CO2 efflux from the fluvial network. Correspondingly, an extreme transformation of running waters into impounded waters (i.e., a twofold increase of the surface area of impounded waters) would triple the CH4 efflux. Thus, carbon emissions from dry beds and impounded waters should be explicitly considered in carbon assessments of fluvial networks, particularly under predicted global change scenarios, which are expected to increase the spatial and temporal extent of these environments. © 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/83472
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 Ecology, University of Barcelona, Av. Diagonal 643, Barcelona, Spain; Department of Plant Biology and Ecology, Faculty of Science and Technology, University of the Basque Country, Apdo. 644, Bilbao, Spain; Catalan Institute for Water Research, Scientific and Technological Park of the University of Girona, Carrer Emili Grahit 101, Girona, Spain; Limnology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18 D, Uppsala, Sweden; Department Lake Research, Helmholtz Centre for Environmental Research, Brückstrasse 3a, Magdeburg, Germany
Recommended Citation:
Gómez-Gener L.,Obrador B.,von Schiller D.,et al. Hot spots for carbon emissions from Mediterranean fluvial networks during summer drought[J]. Biogeochemistry,2015-01-01,125(3)