Growth adjustments of conifers to drought and to century-long irrigation
Growth adjustments of conifers to drought and to century-long irrigation
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DOI：
10.1016/j.foreco.2014.08.008
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发表时间：
2014-12-15
影响因子：
3.7
通讯作者：
Rigling, Andreas
中科院分区：
文献类型：
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作者：
Feichtinger, Linda M.;Eilmann, Britta;Rigling, Andreas
我们对树木对干旱的反应的了解主要是基于短期的操作实验，这些实验没有捕捉到这种反应中任何可能的长期调整。因此，历史上的水渠道内阿尔卑斯山干旱河谷被用来作为长达一个世纪的灌溉实验，以调查树木生长的调整，对比供水。这涉及到量化灌溉和非灌溉（对照）苏格兰松（樟子松L。）在瓦莱州（瑞士），以及欧洲落叶松（落叶松decidua Mill.）和黑松（Pinus nigra Arnold）在文斯高（意大利）。与对照相比，灌溉促进了所有树种的径向生长：（1）直接通过增加土壤水分有效性，（2）间接通过增加灌溉样地土壤养分和腐殖质含量。灌溉导致完全消除欧洲落叶松和黑松对气候的生长反应，但不是苏格兰松，这可能会变得更加敏感，在瓦莱州树木的大小增加干旱。对于对照树，晚材增量的响应，在7月/8月的可用水减少，在最近几十年的所有物种，但在5月增加的苏格兰松。突然停止灌溉导致径向生长下降到一个较低的水平苏格兰松或类似的水平落叶松相比，控制长达十年。然而，这两个树种，然后能够调整到新的条件下，随后增长相似（苏格兰松），甚至更高的增长率（落叶松）比control.To估计气候变化对未来森林发展的影响，操作实验的持续时间应在较长的时间尺度上，以捕捉调整过程和森林生态系统的反馈机制。(C)2014由Elsevier B. V.出版
Our knowledge on tree responses to drought is mainly based on short-term manipulation experiments which do not capture any possible long-term adjustments in this response. Therefore, historical water channels in inner-Alpine dry valleys were used as century-long irrigation experiments to investigate adjustments in tree growth to contrasting water supply. This involved quantifying the tree-ring growth of irrigated and non-irrigated (control) Scots pine (Pinus sylvestris L.) in Valais (Switzerland), as well as European larch (Larix decidua Mill.) and black pine (Pinus nigra Arnold) in Vinschgau (Italy). Furthermore, the adjustments in radial growth of Scots pine and European larch to an abrupt stop in irrigation were analyzed.Irrigation promoted the radial growth of all tree species investigated compared to the control: (1) directly through increased soil water availability, and (2) indirectly through increased soil nutrients and humus contents in the irrigated plots. Irrigation led to a full elimination of growth responses to climate for European larch and black pine, but not for Scots pine, which might become more sensitive to drought with increasing tree size in Valais. For the control trees, the response of the latewood increment to water availability in July/August has decreased in recent decades for all species, but increased in May for Scots pine only. The sudden irrigation stop caused a drop in radial growth to a lower level for Scots pine or similar level for larch compared to the control for up to ten years. However, both tree species were then able to adjust to the new conditions and subsequently grew with similar (Scots pine) or even higher growth rates(larch) than the control.To estimate the impact of climate change on future forest development, the duration of manipulation experiments should be on longer time scales in order to capture adjustment processes and feedback mechanisms of forest ecosystems. (C) 2014 Published by Elsevier B.V.