Climate‐driven speedup of alpine treeline forest growth in the Tianshan Mountains, Northwestern China
Climate‐driven speedup of alpine treeline forest growth in the Tianshan Mountains, Northwestern China
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DOI：
10.1111/gcb.12703
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发表时间：
2015-02
影响因子：
11.6
通讯作者：
Zhaohuan Qi;Hongyan Liu;Xiuchen Wu;Qian Hao
中科院分区：
文献类型：
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作者：
Zhaohuan Qi;Hongyan Liu;Xiuchen Wu;Qian Hao
高山林线交错带(ATE)森林生长对年际气候变化十分敏感。在气候变化的情况下，高山林线交错带是否与低海拔封闭式林带(CFB)具有类似的森林生长模式尚不清楚。本文报道了自20世纪60年代以来，天山云杉林在中国西北部天山口的生长速度出现了前所未有的加速。我们沿着6个垂直样带进行了林分总抽样，每个样带3个样地：1个来自林线和林线之间的样地，另外2个来自CFB。所有取样的天山松林斑块在1960年后都表现出较快的生长速度，相比之下，CFB中的森林生长速度比ATE中的要慢得多。ATE森林生长的加速主要受气候因素的影响，气温升高是主要驱动因素。更强的水分亏缺以及CFB内更多的竞争可能比ATE内更多地限制了那里的森林生长，这意味着生物因素对ATE内森林生长的加速也是重要的，这应该被排除在气候变暖诱导的林线动态的模拟和预测之外。
Forest growth is sensitive to interannual climatic change in the alpine treeline ecotone (ATE). Whether the alpine treeline ecotone shares a similar pattern of forest growth with lower elevational closed forest belt (CFB) under changing climate remains unclear. Here, we reported an unprecedented acceleration of Picea schrenkiana forest growth since 1960s in the ATE of Tianshan Mountains, northwestern China by a stand‐total sampling along six altitudinal transects with three plots in each transect: one from the ATE between the treeline and the forest line, and the other two from the CFB. All the sampled P. schrenkiana forest patches show a higher growth speed after 1960 and, comparatively, forest growth in the CFB has sped up much slower than that in the ATE. The speedup of forest growth at the ATE is mainly accounted for by climate factors, with increasing temperature suggested to be the primary driver. Stronger water deficit as well as more competition within the CFB might have restricted forest growth there more than that within the ATE, implying biotic factors were also significant for the accelerated forest growth in the ATE, which should be excluded from simulations and predictions of warming‐induced treeline dynamics.