Nature：气候变化速度快于物种迁移速度

作者：王韵壹、李英、熊慧卿

专题：Nature报道

发生气候变化时，物种若要继续呆在具有相同平均温度的一个地区，它们就必须迁移：因此，它们的存活机会取决于它们跟气候迁移保持同步的能力以及温度和其他气候因素变化的程度。

为了在具体环境中来说明物种所承受的这种压力，研究人员建立了设计用来对下一世纪气候变化进行量化的一个新指数。该指数值给出了维持温度不变所需的沿地球表面迁移的局部速度，是从以距离和时间为刻度的温度梯度（单位分别为oC per km和oC per year）得出的。

这个指数对地形在缓冲气候变化对植物和动物影响方面所起作用做出了定量描述：在政府间气候变化专门委员会（IPCC）的A1B排放情景中，该指数的全球平均值为0.42 公里/年，而其对山地森林生物群落和淹没草地两种环境的极端值分别为0.08 和1.26公里/年。结果表明，气候变化速度相对于物种迁移速度和受保护生境大小来说是比较大的。

这些数据还表明，在一些生态系统中，通过生境走廊或新的保护区来帮助物种更快迁移，对保护工作可能会是一个重要贡献。（生物谷Bioon.com）

生物谷推荐原始出处：

Nature 462, 1052-1055 (24 December 2009) | doi:10.1038/nature08649

The velocity of climate change

Scott R. Loarie1, Philip B. Duffy1,2, Healy Hamilton3, Gregory P. Asner1, Christopher B. Field1 & David D. Ackerly4

1 Carnegie Institution for Science, Department of Global Ecology, Stanford, California 94305, USA
2 Climate Central, Inc., Palo Alto, California 94301, USA
3 Center for Applied Biodiversity Informatics, California Academy of Sciences, San Francisco, California 94118, USA
4 Department of Integrative Biology, University of California, Berkeley, California 94720, USA
5 Correspondence to: Scott R. Loarie1 Correspondence and requests for materials should be addressed to S.R.L.

The ranges of plants and animals are moving in response to recent changes in climate1. As temperatures rise, ecosystems with ‘nowhere to go’, such as mountains, are considered to be more threatened2, 3. However, species survival may depend as much on keeping pace with moving climates as the climate’s ultimate persistence4, 5. Here we present a new index of the velocity of temperature change (km yr-1), derived from spatial gradients (°C km-1) and multimodel ensemble forecasts of rates of temperature increase (°C?yr-1) in the twenty-first century. This index represents the instantaneous local velocity along Earth’s surface needed to maintain constant temperatures, and has a global mean of 0.42?km?yr-1 (A1B emission scenario). Owing to topographic effects, the velocity of temperature change is lowest in mountainous biomes such as tropical and subtropical coniferous forests (0.08?km?yr-1), temperate coniferous forest, and montane grasslands. Velocities are highest in flooded grasslands (1.26?km?yr-1), mangroves and deserts. High velocities suggest that the climates of only 8% of global protected areas have residence times exceeding 100?years. Small protected areas exacerbate the problem in Mediterranean-type and temperate coniferous forest biomes. Large protected areas may mitigate the problem in desert biomes. These results indicate management strategies for minimizing biodiversity loss from climate change. Montane landscapes may effectively shelter many species into the next century. Elsewhere, reduced emissions, a much expanded network of protected areas6, or efforts to increase species movement may be necessary7.