DOI: 10.1111/gcb.12852
论文题名: Greater deciduous shrub abundance extends tundra peak season and increases modeled net CO<inf>2</inf> uptake
作者: Sweet S.K. ; Griffin K.L. ; Steltzer H. ; Gough L. ; Boelman N.T.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2015
卷: 21, 期: 6 起始页码: 2394
结束页码: 2409
语种: 英语
英文关键词: Alaska
; Arctic tundra
; Canopy phenology
; CO2 flux
; Deciduous shrub abundance
; Net ecosystem exchange
; Normalized difference vegetation index (NDVI)
Scopus关键词: arctic environment
; canopy
; carbon dioxide
; leaf area index
; NDVI
; net ecosystem exchange
; phenology
; plant community
; relative abundance
; shrub
; tundra
; Alaska
; United States
; carbon
; carbon dioxide
; snow
; Alaska
; Arctic
; carbon cycle
; climate change
; metabolism
; plant
; plant leaf
; remote sensing
; season
; temperature
; tundra
; Alaska
; Arctic Regions
; Carbon
; Carbon Cycle
; Carbon Dioxide
; Climate Change
; Plant Leaves
; Plants
; Remote Sensing Technology
; Seasons
; Snow
; Temperature
; Tundra
英文摘要: Satellite studies of the terrestrial Arctic report increased summer greening and longer overall growing and peak seasons since the 1980s, which increases productivity and the period of carbon uptake. These trends are attributed to increasing air temperatures and reduced snow cover duration in spring and fall. Concurrently, deciduous shrubs are becoming increasingly abundant in tundra landscapes, which may also impact canopy phenology and productivity. Our aim was to determine the influence of greater deciduous shrub abundance on tundra canopy phenology and subsequent impacts on net ecosystem carbon exchange (NEE) during the growing and peak seasons in the arctic foothills region of Alaska. We compared deciduous shrub-dominated and evergreen/graminoid-dominated community-level canopy phenology throughout the growing season using the normalized difference vegetation index (NDVI). We used a tundra plant-community-specific leaf area index (LAI) model to estimate LAI throughout the green season and a tundra-specific NEE model to estimate the impact of greater deciduous shrub abundance and associated shifts in both leaf area and canopy phenology on tundra carbon flux. We found that deciduous shrub canopies reached the onset of peak greenness 13 days earlier and the onset of senescence 3 days earlier compared to evergreen/graminoid canopies, resulting in a 10-day extension of the peak season. The combined effect of the longer peak season and greater leaf area of deciduous shrub canopies almost tripled the modeled net carbon uptake of deciduous shrub communities compared to evergreen/graminoid communities, while the longer peak season alone resulted in 84% greater carbon uptake in deciduous shrub communities. These results suggest that greater deciduous shrub abundance increases carbon uptake not only due to greater leaf area, but also due to an extension of the period of peak greenness, which extends the period of maximum carbon uptake. © 2015 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/61635
Appears in Collections: 影响、适应和脆弱性
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作者单位: Lamont-Doherty Earth Observatory, Department of Earth and Environmental Sciences, Columbia University, Palisades, NY, United States; Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York, NY, United States; Department of Biology, Fort Lewis College, Durango, CO, United States; Department of Biology, University of Texas at Arlington, Arlington, TX, United States
Recommended Citation:
Sweet S.K.,Griffin K.L.,Steltzer H.,et al. Greater deciduous shrub abundance extends tundra peak season and increases modeled net CO<inf>2</inf> uptake[J]. Global Change Biology,2015-01-01,21(6)