Muséum National d'Histoire Naturelle, UMR 7204 MNHN-CNRS-UPMC, Centre de Recherches sur la Biologie des Populations d'Oiseaux, 75005 Paris, France.
Proc Biol Sci. 2010 Dec 7;277(1700):3601-8. doi: 10.1098/rspb.2010.0796. Epub 2010 Jun 16.
Beyond the effects of temperature increase on local population trends and on species distribution shifts, how populations of a given species are affected by climate change along a species range is still unclear. We tested whether and how species responses to climate change are related to the populations locations within the species thermal range. We compared the average 20 year growth rates of 62 terrestrial breeding birds in three European countries along the latitudinal gradient of the species ranges. After controlling for factors already reported to affect bird population trends (habitat specialization, migration distance and body mass), we found that populations breeding close to the species thermal maximum have lower growth rates than those in other parts of the thermal range, while those breeding close to the species thermal minimum have higher growth rates. These results were maintained even after having controlled for the effect of latitude per se. Therefore, the results cannot solely be explained by latitudinal clines linked to the geographical structure in local spring warming. Indeed, we found that populations are not just responding to changes in temperature at the hottest and coolest parts of the species range, but that they show a linear graded response across their European thermal range. We thus provide insights into how populations respond to climate changes. We suggest that projections of future species distributions, and also management options and conservation assessments, cannot be based on the assumption of a uniform response to climate change across a species range or at range edges only.
除了温度升高对当地种群趋势和物种分布变化的影响外，气候变化如何影响给定物种在物种分布范围内的种群仍然不清楚。我们测试了物种对气候变化的反应是否以及如何与物种热范围内的种群位置有关。我们比较了三个欧洲国家沿物种分布范围纬度梯度的 62 种陆生繁殖鸟类的平均 20 年增长率。在控制已经报道的影响鸟类种群趋势的因素（生境特化、迁徙距离和体重）后，我们发现，在接近物种热最大值的地方繁殖的种群的增长率低于热范围内其他地方的种群，而在接近物种热最小值的地方繁殖的种群的增长率则更高。即使在控制了纬度本身的影响之后，这些结果仍然成立。因此，这些结果不能仅仅用与当地春季变暖的地理结构有关的纬度梯度来解释。事实上，我们发现，种群不仅对物种分布范围最热和最冷部分的温度变化做出反应，而且在整个欧洲热范围内表现出线性梯度反应。因此，我们深入了解了种群对气候变化的反应。我们认为，未来物种分布的预测，以及管理选择和保护评估，不能基于在物种分布范围内或仅在分布范围边缘对气候变化的统一反应的假设。
