文章基本信息

标题：Long-term increases in snow pack elevate leaf N and photosynthesis in Salix arctica: responses to a snow fence experiment in the High Arctic of NW Greenland
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作者：A Joshua Leffler ; Jeffery M Welker
期刊名称：Environmental Research Letters
印刷版ISSN：1748-9326
电子版ISSN：1748-9326
出版年度：2013
卷号：8
期号：2
页码：025023
DOI：10.1088/1748-9326/8/2/025023
语种：English
出版社：IOP Publishing Ltd
摘要：We examine the influence of altered winter precipitation on a High Arctic landscape with continuous permafrost. Gas exchange, leaf tissue element and isotopic composition (N, δ¹³C, δ¹⁵N), and plant water sources derived from stem and soil water δ¹⁸O were examined in Salix arctica (arctic willow) following a decade of snow-fence-enhanced snow pack in NW Greenland. Study plots in ambient and +snow conditions were sampled in summer 2012. Plants experiencing enhanced snow conditions for 10 years had higher leaf [N], photosynthetic rate, and more enriched leaf δ¹⁵N. Enhanced snow did not influence stomatal conductance or depth of plant water use. We attribute the higher photosynthetic rate in S. arctica exposed to deeper snow pack to altered biogeochemical cycles which yielded higher leaf [N] rather than to enhanced water availability. These data demonstrate the complexity of High Arctic plant responses to changes in winter conditions. Furthermore, our data depict the intricate linkages between winter and summer conditions as they regulate processes such as leaf gas exchange that may control water vapor and CO₂ feedbacks between arctic tundra and the surrounding atmosphere.