Greater vulnerability to warming of marine versus terrestrial ectotherms
Greater vulnerability to warming of marine versus terrestrial ectotherms
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DOI：
10.1038/s41586-019-1132-4
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发表时间：
2019-05-02
期刊：
影响因子：
64.8
通讯作者：
Sunday, Jennifer M.
中科院分区：
文献类型：
--
作者：
Pinsky, Malin L.;Eikeset, Anne Maria;Sunday, Jennifer M.
随着气候变化的推进，了解哪些物种和生态系统将受到气候变暖的最严重影响，对于指导保护和管理非常重要。海洋和陆地动物都受到了气候变暖的影响(1，2)，但对海洋和陆地之间的生理敏感性缺乏明确的比较。评估种群与其温度上限的距离一直是具有挑战性的，部分原因是极端温度经常驱动人口反应(3，4)，而动物可以利用当地的热避难所来避开极端(5-7)。在这里，我们展示了海洋外温动物每小时的体温比所有纬度的陆地外温动物更接近其体温上限--但只有在陆地物种可以进入热避难所的情况下才是这样。虽然不是人口下降的直接预测，但这一热安全裕度提供了气候变暖造成的生理压力的指标。在陆地上，每小时体温最高的中纬度物种的热安全裕度最小；相比之下，赤道附近的海洋物种的热安全裕度最小。我们还发现，与变暖有关的局部灭绝在海洋中是陆地上的两倍，这与海上较小的热安全裕度是一致的。我们的结果表明，不同的过程将加剧这两个领域的热脆弱性。海洋领域对变暖的更高敏感性和更快的殖民化速度表明，海洋中的灭绝将更加频繁，物种更替将更快。相比之下，陆地物种似乎更容易失去热避难所，这将使栖息地碎片化和土地使用的变化成为陆地物种丧失的关键驱动因素。
Understanding which species and ecosystems will be most severely affected by warming as climate change advances is important for guiding conservation and management. Both marine and terrestrial fauna have been affected by warming(1,2) but an explicit comparison of physiological sensitivity between the marine and terrestrial realms has been lacking. Assessing how close populations live to their upper thermal limits has been challenging, in part because extreme temperatures frequently drive demographic responses(3,4) and yet fauna can use local thermal refugia to avoid extremes(5-7). Here we show that marine ectotherms experience hourly body temperatures that are closer to their upper thermal limits than do terrestrial ectotherms across all latitudes-but that this is the case only if terrestrial species can access thermal refugia. Although not a direct prediction of population decline, this thermal safety margin provides an index of the physiological stress caused by warming. On land, the smallest thermal safety margins were found for species at mid-latitudes where the hottest hourly body temperatures occurred; by contrast, the marine species with the smallest thermal safety margins were found near the equator. We also found that local extirpations related to warming have been twice as common in the ocean as on land, which is consistent with the smaller thermal safety margins at sea. Our results suggest that different processes will exacerbate thermal vulnerability across these two realms. Higher sensitivities to warming and faster rates of colonization in the marine realm suggest that extirpations will be more frequent and species turnover faster in the ocean. By contrast, terrestrial species appear to be more vulnerable to loss of access to thermal refugia, which would make habitat fragmentation and changes in land use critical drivers of species loss on land.