DOI: 10.1002/2013GB004685
Scopus记录号: 2-s2.0-84893168840
论文题名: Regional contribution of CO2 and CH4 fluxes from the fluvial network in a lowland boreal landscape of Québec
作者: Campeau A ; , Lapierre J ; -F ; , Vachon D ; , Del Giorgio P ; A
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2014
卷: 28, 期: 1 起始页码: 57
结束页码: 69
语种: 英语
英文关键词: fluvial networks
; greenhouse gases
; rivers
; stream
Scopus关键词: Gas emissions
; Greenhouse gases
; Methane
; Rivers
; Thawing
; Boreal regions
; Boreal rivers
; Emission budgets
; Gas-exchange coefficients
; Regional pattern
; River continuum
; Rivers and streams
; stream
; Carbon dioxide
; boreal forest
; carbon dioxide
; carbon emission
; carbon flux
; lowland environment
; methane
; regional pattern
; Canada
; Quebec [Canada]
英文摘要: Boreal rivers and streams are known as hot spots of CO2 emissions, yet their contribution to CH4 emissions has traditionally been assumed to be negligible, due to the spatially fragmented data and lack of regional studies addressing both gases simultaneously. Here we explore the regional patterns in river CO2 and CH4 concentrations (pCO2 and pCH4), gas exchange coefficient (k), and the resulting emissions in a lowland boreal region of Northern Québec. Rivers and streams were systematically supersaturated in both gases, with both pCO2 and pCH4 declining along the river continuum. The k was on average low and increased with stream order, consistent with the hydrology of this flat landscape. The smallest streams (order 1), which represent < 20% of the total river surface, contributed over 35% of the total fluvial greenhouse gas (GHG) emissions. The end of winter and the spring thaw periods, which are rarely included in annual emission budgets, contributed on average 21% of the annual GHG emissions. As a whole, the fluvial network acted as significant source of both CO2 and CH4, releasing on average 1.5 tons of C (CO2 eq) yr-1 km-2 of landscape, of which CH4 emissions contributed approximately 34%. We estimate that fluvial CH4 emissions represent 41% of the regional aquatic (lakes, reservoirs, and rivers) CH4 emissions, despite the relatively small riverine surface (4.3% of the total aquatic surface). We conclude that these fluvial networks in boreal lowlands play a disproportionately large role as hot spots for CO2 and more unexpectedly for CH4 emissions. Key Points pCO2 and pCH4 decrease, whereas the k600 increases with increasing stream order Small streams and spring thaw period play a large role in regional C balance Rivers are significant sources of CO2 and unexpectedly large sources of CH4 ©2014. 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/77468
Appears in Collections: 气候变化事实与影响
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作者单位: Groupe de Recherche Interuniversitaire en Limnologie et en Environnement Aquatique, Département des Sciences Biologiques, Université du Québec À Montréal, Montréal, QC, Canada; Now at Department of Earth Sciences, Air, Water and Landscape Sciences, Uppsala University, Uppsala, Sweden
Recommended Citation:
Campeau A,, Lapierre J,-F,et al. Regional contribution of CO2 and CH4 fluxes from the fluvial network in a lowland boreal landscape of Québec[J]. Global Biogeochemical Cycles,2014-01-01,28(1)