DOI: 10.1111/gcb.13747
论文题名: High Arctic summer warming tracked by increased Cassiope tetragona growth in the world's northernmost polar desert
作者: Weijers S. ; Buchwal A. ; Blok D. ; Löffler J. ; Elberling B.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2017
语种: 英语
英文关键词: Climate change
; Dendrochronology
; Dendroecology
; Dwarf shrubs
; Early twentieth-century warming
; North Atlantic Oscillation
; Shrub expansion
; Soil moisture
; Temperature proxy
; Tundra
英文摘要: Rapid climate warming has resulted in shrub expansion, mainly of erect deciduous shrubs in the Low Arctic, but the more extreme, sparsely vegetated, cold and dry High Arctic is generally considered to remain resistant to such shrub expansion in the next decades. Dwarf shrub dendrochronology may reveal climatological causes of past changes in growth, but is hindered at many High Arctic sites by short and fragmented instrumental climate records. Moreover, only few High Arctic shrub chronologies cover the recent decade of substantial warming. This study investigated the climatic causes of growth variability of the evergreen dwarf shrub Cassiope tetragona between 1927 and 2012 in the northernmost polar desert at 83°N in North Greenland. We analysed climate-growth relationships over the period with available instrumental data (1950-2012) between a 102-year-long C. tetragona shoot length chronology and instrumental climate records from the three nearest meteorological stations, gridded climate data, and North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) indices. July extreme maximum temperatures (JulTemx), as measured at Alert, Canada, June NAO, and previous October AO, together explained 41% of the observed variance in annual C. tetragona growth and likely represent in situ summer temperatures. JulTemx explained 27% and was reconstructed back to 1927. The reconstruction showed relatively high growing season temperatures in the early to mid-twentieth century, as well as warming in recent decades. The rapid growth increase in C. tetragona shrubs in response to recent High Arctic summer warming shows that recent and future warming might promote an expansion of this evergreen dwarf shrub, mainly through densification of existing shrub patches, at High Arctic sites with sufficient winter snow cover and ample water supply during summer from melting snow and ice as well as thawing permafrost, contrasting earlier notions of limited shrub growth sensitivity to summer warming in the High Arctic. © 2017 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/61208
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Geography University of Bonn Bonn Germany; Institute of Geoecology and Geoinformation Adam Mickiewicz University Poznan Poland; Department of Biological Sciences Ecosystem and Biomedical Lab University of Alaska Anchorage Anchorage, AK USA; Department of Physical Geography and Ecosystem Science Lund University Lund Sweden; Center for Permafrost (CENPERM) Department of Geosciences and Natural Resource Management University of Copenhagen Copenhagen Denmark
Recommended Citation:
Weijers S.,Buchwal A.,Blok D.,et al. High Arctic summer warming tracked by increased Cassiope tetragona growth in the world's northernmost polar desert[J]. Global Change Biology,2017-01-01