Early establishment of trees at the alpine treeline: idiosyncratic species responses to temperature-moisture interactions
Early establishment of trees at the alpine treeline: idiosyncratic species responses to temperature-moisture interactions
复制标题
高山林线树木的早期生长：特殊物种对温度-湿度相互作用的反应
DOI：
10.1093/aobpla/plw053
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发表时间：
2016
期刊：
影响因子：
2.9
通讯作者：
M.Y. Bader
中科院分区：
文献类型：
--
作者：
Loranger;G. Zotz ;M.Y. Bader
在全球范围内，温度是北极和高山树线位置的主要决定因素。然而，在局部范围内，由于其他气候因素，树种生态和生命阶段依赖的反应，树线的形式和位置变化很大。对于树木走向极地或上坡，第一步是发芽和幼苗建立。这些最早期的生命阶段可能是树线树木种群的主要瓶颈，并且与成年树木相比，它们取决于不同的气候条件。我们调查了土壤温度和湿度对发芽和早期幼苗存活的影响，在法国阿尔卑斯山附近的当地树线（2100米a.s.l.）使用被动温度控制和两种浇水方式。研究了五种欧洲树线树种：落叶落叶松、欧洲云杉、欧洲赤松、欧洲赤松和欧洲花楸。此外，我们监测了这些物种中的三个在生长室中的受控条件下对低温的发芽反应。这些树木在高山树线的早期建立受到温度或湿度的限制，对一个因素的敏感性往往取决于另一个因素的强度。结果表明，这两个因素的相对重要性和方向的影响是高度物种特异性的，而这两个因素往往有一致的影响发芽和早期幼苗存活在每个物种。我们表明，温度和水的可用性都是重要的贡献者建立模式的树线树木，因此物种特异性的形式和位置的高山树线。所观察到的特异质物种的反应，强调需要研究，包括几个物种和生命阶段，以创造预测能力，未来的树线动态。
On a global scale, temperature is the main determinant of arctic and alpine treeline position. However on a local scale, treeline form and position vary considerably due to other climatic factors, tree species ecology and life-stage-dependent responses. For treelines to advance poleward or uphill, the first steps are germination and seedling establishment. These earliest life stages may be major bottlenecks for treeline tree populations and will depend differently on climatic conditions than adult trees. We investigated the effect of soil temperature and moisture on germination and early seedling survival in a field experiment in the French Alps near the local treeline (2100 m a.s.l.) using passive temperature manipulations and two watering regimes. Five European treeline tree species were studied:Larix decidua,Picea abies,Pinus cembra,Pinus uncinataandSorbus aucuparia. In addition, we monitored the germination response of three of these species to low temperatures under controlled conditions in growth chambers. The early establishment of these trees at the alpine treeline was limited either by temperature or by moisture, the sensitivity to one factor often depending on the intensity of the other. The results showed that the relative importance of the two factors and the direction of the effects are highly species-specific, while both factors tend to have consistent effects on both germination and early seedling survival within each species. We show that temperature and water availability are both important contributors to establishment patterns of treeline trees and hence to species-specific forms and positions of alpine treelines. The observed idiosyncratic species responses highlight the need for studies including several species and life-stages to create predictive power concerning future treeline dynamics.