DOI: 10.1029/2018JG004468
Scopus记录号: 2-s2.0-85052631553
论文题名: Catchment-Scale Shifts in the Magnitude and Partitioning of Carbon Export in Response to Changing Hydrologic Connectivity in a Northern Hardwood Forest
作者: Senar O.E. ; Webster K.L. ; Creed I.F.
刊名: Journal of Geophysical Research: Biogeosciences
ISSN: 21698953
出版年: 2018
卷: 123, 期: 8 起始页码: 2337
结束页码: 2352
语种: 英语
英文关键词: carbon dioxide
; dissolved organic carbon
; forest
; hydrologic connectivity
; soil organic carbon
英文摘要: The capacity of forest soils to store organic carbon is influenced by changing hydrologic connectivity. We hypothesized that hydrologic connectivity, the water-mediated transfer of matter and energy between different landscape positions, controls the partitioning between aquatic and atmospheric soil carbon fates. Results from a 5-year study of a northern hardwood forested catchment indicated that hydrologic connectivity affected both the magnitude and fate of carbon export. Atmospheric carbon export was the major export pathway from the catchment; its rate was regulated by topographic position (i.e., uplands, ecotones, and wetlands) but enhanced or supressed through changes in soil moisture and hydrologic connectivity. Wetter soil conditions reduced CO2 flux from the ecotones and wetlands where microbial respiration was oxygen-limited, whereas drier soil conditions that decreased hydrologic connectivity increased CO2 flux by relieving the oxygen limitation. In contrast, aquatic carbon export was a minor export pathway from the catchment and was driven by hydrologic connectivity, with less carbon export during relatively low discharge years. Past trends suggest a shift to a warmer climate and changes in the timing, duration, and intensity of hydrologic connectivity that are leading to an increase in annual atmospheric carbon export but a decrease in annual aquatic carbon export, despite the intensification of autumn storms. The increase in atmospheric carbon export creates a positive feedback for climate warming that will further disrupt hydrologic connectivity and aquatic carbon export, with consequences for downstream streams and lakes. ©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/113406
Appears in Collections: 气候减缓与适应
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作者单位: Department of Geography, Western University, London, ON, Canada; Natural Resources Canada, Canadian Forest Service, Sault Ste. Marie, ON, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, Canada; Department of Biology, Western University, London, ON, Canada
Recommended Citation:
Senar O.E.,Webster K.L.,Creed I.F.. Catchment-Scale Shifts in the Magnitude and Partitioning of Carbon Export in Response to Changing Hydrologic Connectivity in a Northern Hardwood Forest[J]. Journal of Geophysical Research: Biogeosciences,2018-01-01,123(8)