Leaf metabolic and morphological responses of dwarf willow (Salix herbacea) in the sub-arctic to the past 9000 years of global environmental change
Leaf metabolic and morphological responses of dwarf willow (Salix herbacea) in the sub-arctic to the past 9000 years of global environmental change
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DOI：
10.1046/j.1469-8137.2000.00582.x
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发表时间：
2000-02-01
期刊：
影响因子：
9.4
通讯作者：
Rundgren, M
中科院分区：
文献类型：
--
作者：
Beerling, DJ;Rundgren, M
冰芯记录的大气二氧化碳浓度及其稳定同位素比率(Delta(13)C(A))表明，全球碳循环在过去11000年中并未保持稳定状态，这意味着这一时期植被活动可能发生了变化。在这里，我们通过测量一个独特的、年代准确的、高纬度(68度)的亚化石叶片序列的稳定碳同位素组成和气孔特征，评估了过去9000年来矮柳(Salix Herbacea)的生态生理响应。在校正了增量(13)C(A)的相应变化后，建立了胞间(c(I))与大气(c(A))二氧化碳浓度比率变化的9000年记录。胞间：大气CO2浓度比提供了叶片气体交换设定点的时间综合指标，这一记录中揭示的历史变化被解释为环境变化对叶片气体交换的影响。该序列显示出c(I)/c(A)9000-3000年BP的逐渐下降，以及中世纪暖期、小冰期和后工业时代二氧化碳上升的气候影响。叶片气孔指数(表皮细胞占气孔的比例)与气孔密度无显著差异(P
Ice-core records of the concentration of atmospheric CO2 and its stable isotope ratio (delta(13)C(a)) have shown that the global C cycle has not remained in steady-state over the past 11000 yr, implying a possible change in vegetation activity over this period. Here we evaluated the ecophysiological responses of the dwarf willow (Salix herbacea) over the past 9000 yr by measuring the stable carbon isotope composition and stomatal characters of a unique, well dated, high-latitude (68 degrees N) sub-fossil leaf sequence. After correction for corresponding changes in delta(13)C(a), a 9000- yr record of variations in the ratio of intercellular (c(i)) to atmospheric (c(a)) CO2 concentration was established. Intercellular: atmospheric CO2 concentration ratios provide a time-integrated indicator of the set-point of leaf gas exchange, and the historical variations revealed in this record have been interpreted as an impact of environmental changes on leaf gas exchange. The sequence shows a progressive fall in c(i)/c(a) 9000-3000 yr BP as well as the climatic effects of the Medieval Warm Period, the Little Ice Age and the post-industrial CO2 rise. Leaf stomatal index (proportion of epidermal cells as stomata), but not stomatal density, was significantly (P