DOI: 10.1111/gcb.13064
论文题名: Net ecosystem exchange of CO2 with rapidly changing high Arctic landscapes
作者: Emmerton C.A. ; St. Louis V.L. ; Humphreys E.R. ; Gamon J.A. ; Barker J.D. ; Pastorello G.Z.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2016
卷: 22, 期: 3 起始页码: 1185
结束页码: 1200
语种: 英语
英文关键词: MODIS
; NDVI
; Carbon dioxide
; Ecosystem respiration
; Eddy covariance
; Gross primary production
; High Arctic
; Landsat
; Net ecosystem exchange
Scopus关键词: carbon dioxide
; Arctic
; carbon cycle
; climate change
; ecosystem
; Nunavut
; season
; Arctic Regions
; Carbon Cycle
; Carbon Dioxide
; Climate Change
; Ecosystem
; Nunavut
; Seasons
英文摘要: High Arctic landscapes are expansive and changing rapidly. However, our understanding of their functional responses and potential to mitigate or enhance anthropogenic climate change is limited by few measurements. We collected eddy covariance measurements to quantify the net ecosystem exchange (NEE) of CO2 with polar semidesert and meadow wetland landscapes at the highest latitude location measured to date (82°N). We coupled these rare data with ground and satellite vegetation production measurements (Normalized Difference Vegetation Index; NDVI) to evaluate the effectiveness of upscaling local to regional NEE. During the growing season, the dry polar semidesert landscape was a near-zero sink of atmospheric CO2 (NEE: -0.3 ± 13.5 g C m-2). A nearby meadow wetland accumulated over 300 times more carbon (NEE: -79.3 ± 20.0 g C m-2) than the polar semidesert landscape, and was similar to meadow wetland NEE at much more southerly latitudes. Polar semidesert NEE was most influenced by moisture, with wetter surface soils resulting in greater soil respiration and CO2 emissions. At the meadow wetland, soil heating enhanced plant growth, which in turn increased CO2 uptake. Our upscaling assessment found that polar semidesert NDVI measured on-site was low (mean: 0.120-0.157) and similar to satellite measurements (mean: 0.155-0.163). However, weak plant growth resulted in poor satellite NDVI-NEE relationships and created challenges for remotely detecting changes in the cycling of carbon on the polar semidesert landscape. The meadow wetland appeared more suitable to assess plant production and NEE via remote sensing; however, high Arctic wetland extent is constrained by topography to small areas that may be difficult to resolve with large satellite pixels. We predict that until summer precipitation and humidity increases enough to offset poor soil moisture retention, climate-related changes to productivity on polar semideserts may be restricted. © 2016 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/61454
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada; Department of Geography and Environmental Studies, Carleton University, Ottawa, ON, Canada; Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB, Canada; School of Earth Sciences, Ohio State University, Marion, OH, United States; Computational Research Division, Lawrence Berkeley National Lab, Berkeley, CA, United States
Recommended Citation:
Emmerton C.A.,St. Louis V.L.,Humphreys E.R.,et al. Net ecosystem exchange of CO2 with rapidly changing high Arctic landscapes[J]. Global Change Biology,2016-01-01,22(3)