DOI: 10.1007/s10533-013-9930-5
Scopus记录号: 2-s2.0-84896399413
论文题名: Nitrogen isotope tracer acquisition in low and tall birch tundra plant communities: A 2 year test of the snow-shrub hypothesis
作者: Vankoughnett M.R. ; Grogan P.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 118, 期: 2018-01-03 起始页码: 291
结束页码: 306
语种: 英语
英文关键词: Arctic
; Increased snow
; Shrub expansion
; Snow-shrub feedback hypothesis
; Winter processes
Scopus关键词: biological uptake
; community composition
; deciduous tree
; evergreen tree
; growth rate
; land cover
; landscape
; microbial activity
; nitrogen cycle
; nitrogen isotope
; plant community
; soil temperature
; Arctic
英文摘要: Deciduous shrub density and landcover are increasing across many areas of the Arctic. Shrub growth may be promoted by a snow-shrub feedback whereby relatively tall shrubs accumulate deeper snow, raising winter soil temperature minima, increasing microbial activity, and enhancing soil solution nitrogen (N). Although there is good evidence for the above components of the hypothesis, it has not yet been determined if shrubs can access the elevated N pool generated by deepened snow. We added isotopic N tracer (15N) in late summer to control and snowfenced low birch hummock tundra to test the influence of deepened snow on N cycling. Furthermore, tracer was added to tall birch tundra to compare N cycling in low and tall shrub ecosystems that have the same species composition. Experimentally deepened snow in low birch tundra did not significantly affect 15N uptake by shrubs or any other species 2 years after the tracer addition. However, there were strong differences between the low and tall birch ecosystems, with the deciduous shrubs and graminoids accumulating more 15N than the evergreen shrubs in the relatively productive tall shrub site, and vice versa in the relatively infertile low birch site. The greater 15N acquisition by birch in the more fertile site, together with the absence of a deepened snow effect on 15N acquisition by any species in the low birch hummock ecosystem, suggest that climate-change induced increases in birch shrub growth and expansion across the landscape will tend to occur most rapidly in and around existing tall birch shrub patches. © 2013 Springer Science+Business Media Dordrecht. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83605
Appears in Collections: 气候减缓与适应 气候变化事实与影响
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作者单位: Department of Biology, University of Western Ontario, N6A 5B7, London, ON, Canada; Department of Biology, Queen's University, K7L 3N6, Kingston, ON, Canada
Recommended Citation:
Vankoughnett M.R.,Grogan P.. Nitrogen isotope tracer acquisition in low and tall birch tundra plant communities: A 2 year test of the snow-shrub hypothesis[J]. Biogeochemistry,2014-01-01,118(2018-01-03)