DOI: 10.1111/gcb.12406
论文题名: Tall shrub and tree expansion in Siberian tundra ecotones since the 1960s
作者: Frost G.V. ; Epstein H.E.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2014
卷: 20, 期: 4 起始页码: 1264
结束页码: 1277
语种: 英语
英文关键词: Alder
; Arctic tundra
; Forest-tundra
; Larch
; Permafrost
; Shrub expansion
; Siberia
; Treeline
Scopus关键词: climate change
; climate effect
; ecosystem response
; ecotone
; landscape change
; permafrost
; satellite data
; tundra
; vegetation dynamics
; Siberia
; Alnus
; Larix
; ice
; Arctic
; climate change
; ecosystem
; Russian Federation
; temperature
; tree
; Arctic Regions
; Climate Change
; Ecosystem
; Ice
; Siberia
; Temperature
; Trees
英文摘要: Circumpolar expansion of tall shrubs and trees into Arctic tundra is widely thought to be occurring as a result of recent climate warming, but little quantitative evidence exists for northern Siberia, which encompasses the world's largest forest-tundra ecotonal belt. We quantified changes in tall shrub and tree canopy cover in 11, widely distributed Siberian ecotonal landscapes by comparing very high-resolution photography from the Cold War-era 'Gambit' and 'Corona' satellite surveillance systems (1965-1969) with modern imagery. We also analyzed within-landscape patterns of vegetation change to evaluate the susceptibility of different landscape components to tall shrub and tree increase. The total cover of tall shrubs and trees increased in nine of 11 ecotones. In northwest Siberia, alder (Alnus) shrubland cover increased 5.3-25.9% in five ecotones. In Taymyr and Yakutia, larch (Larix) cover increased 3.0-6.7% within three ecotones, but declined 16.8% at a fourth ecotone due to thaw of ice-rich permafrost. In Chukotka, the total cover of alder and dwarf pine (Pinus) increased 6.1% within one ecotone and was little changed at a second ecotone. Within most landscapes, shrub and tree increase was linked to specific geomorphic settings, especially those with active disturbance regimes such as permafrost patterned-ground, floodplains, and colluvial hillslopes. Mean summer temperatures increased at most ecotones since the mid-1960s, but rates of shrub and tree canopy cover expansion were not strongly correlated with temperature trends and were better correlated with mean annual precipitation. We conclude that shrub and tree cover is increasing in tundra ecotones across most of northern Siberia, but rates of increase vary widely regionally and at the landscape scale. Our results indicate that extensive changes can occur within decades in moist, shrub-dominated ecotones, as in northwest Siberia, while changes are likely to occur much more slowly in the highly continental, larch-dominated ecotones of central and eastern Siberia. © 2013 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/61949
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Environmental Sciences, University of Virginia, P.O Box 400123, Charlottesville, VA 22903, United States; ABR, Inc. Environmental Research and Services, P.O. Box 80410, Fairbanks, AK 99708, United States
Recommended Citation:
Frost G.V.,Epstein H.E.. Tall shrub and tree expansion in Siberian tundra ecotones since the 1960s[J]. Global Change Biology,2014-01-01,20(4)