Global distribution and climatic controls of natural mountain treelines
Global distribution and climatic controls of natural mountain treelines
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DOI：
10.1111/gcb.16885
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发表时间：
2023-07-21
影响因子：
11.6
通讯作者：
Zeng, Zhenzhong
中科院分区：
文献类型：
--
作者：
He, Xinyue;Jiang, Xin;Zeng, Zhenzhong
山区树木线被认为对气候变化很敏感。然而，气候如何影响山地树木线尚未完全了解，因为树木线也可能受到其他人类活动的影响。在这里，我们专注于“闭环”的山地树线（CLMT），完全包围一座山，不太可能受到人类土地利用变化的影响。我们在全球243座山脉中检测到总长度接近916，425公里的CLMT，并揭示了树线海拔的双峰纬度分布，其中距离海岸较远的地方树线海拔较高。在空间上，我们发现，温度是主要的气候驱动力的树线海拔在北方和热带地区，而降水驱动CLMT的位置在温带。从时间上看，我们发现70%的CLMT已经向上移动，在21世纪的第一个十年中，平均移动速率为1.2米/年。CLMT在热带移动最快（平均3.1米/年），但变异性更大。我们的工作提供了一个新的山区树线数据库，将气候影响与其他人为压力隔离开来，并对气候变化中的生物多样性，自然资源和生态系统适应具有重要意义。
Mountain treelines are thought to be sensitive to climate change. However, how climate impacts mountain treelines is not yet fully understood as treelines may also be affected by other human activities. Here, we focus on "closed-loop" mountain treelines (CLMT) that completely encircle a mountain and are less likely to have been influenced by human land-use change. We detect a total length of similar to 916,425 km of CLMT across 243 mountain ranges globally and reveal a bimodal latitudinal distribution of treeline elevations with higher treeline elevations occurring at greater distances from the coast. Spatially, we find that temperature is the main climatic driver of treeline elevation in boreal and tropical regions, whereas precipitation drives CLMT position in temperate zones. Temporally, we show that 70% of CLMT have moved upward, with a mean shift rate of 1.2 m/year over the first decade of the 21st century. CLMT are shifting fastest in the tropics (mean of 3.1 m/year), but with greater variability. Our work provides a new mountain treeline database that isolates climate impacts from other anthropogenic pressures, and has important implications for biodiversity, natural resources, and ecosystem adaptation in a changing climate.