Changes in Climatic Water Balance Drive Downhill Shifts in Plant Species' Optimum Elevations
Changes in Climatic Water Balance Drive Downhill Shifts in Plant Species' Optimum Elevations
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DOI：
10.1126/science.1199040
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发表时间：
2011-01-21
期刊：
影响因子：
56.9
通讯作者：
Mynsberge, Alison R.
中科院分区：
文献类型：
--
作者：
Crimmins, Shawn M.;Dobrowski, Solomon Z.;Mynsberge, Alison R.
物种分布对历史变暖的上行变化有很好的记录，这导致人们普遍预期，在未来变暖的情况下，物种分布会继续上行变化。相反，下坡变化通常被认为是异常的，与气候变化无关。通过比较20世纪30年代和现在加州境内植物物种的海拔分布，我们发现气候变化导致物种的最适海拔显著下移。这种走下坡路的转变与20世纪全球变暖的预期相反，但很容易用物种对气候水平衡而不是温度的区域变化的生态位跟踪来解释。在未来气候变化情景预计可用水增加的速度超过蒸发需求的情况下，可能会出现类似的下行变化。
Uphill shifts of species' distributions in response to historical warming are well documented, which leads to widespread expectations of continued uphill shifts under future warming. Conversely, downhill shifts are often considered anomalous and unrelated to climate change. By comparing the altitudinal distributions of 64 plant species between the 1930s and the present day within California, we show that climate changes have resulted in a significant downward shift in species' optimum elevations. This downhill shift is counter to what would be expected given 20th-century warming but is readily explained by species' niche tracking of regional changes in climatic water balance rather than temperature. Similar downhill shifts can be expected to occur where future climate change scenarios project increases in water availability that outpace evaporative demand.