Physiological constraints on organismal response to global warming: mechanistic insights from clinally varying populations and implications for assessing endangerment
Physiological constraints on organismal response to global warming: mechanistic insights from clinally varying populations and implications for assessing endangerment
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DOI：
10.1098/rsbl.2005.0417
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发表时间：
2006-03-22
期刊：
影响因子：
3.3
通讯作者：
Spotila, James R.
中科院分区：
文献类型：
--
作者：
Bernardo, Joseph;Spotila, James R.
最近的综合研究表明，全球变暖影响了各种生物过程，但也突出了一些物种在行为或进化上适应快速气候变化的潜力。很少有人关注另一种选择，即缺乏这种能力的生物可能面临灭绝，这一命运预计将降临到全球四分之一的生物多样性上。这一结论是有争议的，部分原因是几乎没有机制研究表明气候变化如何加速灭绝。我们提供了一个具体的，机械的例子，变暖的压力源的生物体，是密切适应凉爽的气候，从比较分析的生物体的耐受性之间的clinally不同的人口沿着一个自然的热梯度。我们发现，两个山地蝾螈表现出显着的代谢抑制在自然温度范围内的低，中海拔人口经历的温度。此外，抑郁症的程度呈负相关的本地海拔，这表明低海拔人群已经生活在他们的生理耐受极限附近。如果这一发现普遍适用于其他山地专家，在典型的多样性山地系统的生物多样性丧失的预测是清醒的。我们建议，变暖引起的胁迫耐受性的指数可能提供一个重要的新工具，定量评估的危害，由于人为的气候变化在不同的物种。
Recent syntheses indicate that global warming affects diverse biological processes, but also highlight the potential for some species to adapt behaviourally or evolutionarily to rapid climate change. Far less attention has addressed the alternative, that organisms lacking this ability may face extinction, a fate projected to befall one-quarter of global biodiversity. This conclusion is controversial, in part because there exist few mechanistic studies that show how climate change could precipitate extinction. We provide a concrete, mechanistic example of warming as a stressor of organisms that are closely adapted to cool climates from a comparative analysis of organismal tolerance among clinally varying populations along a natural thermal gradient. We found that two montane salamanders exhibit significant metabolic depression at temperatures within the natural thermal range experienced by low and middle elevation populations. Moreover, the magnitude of depression was inversely related to native elevation, suggesting that low elevation populations are already living near the limit of their physiological tolerances. If this finding generally applies to other montane specialists, the prognosis for biodiversity loss in typically diverse montane systems is sobering. We propose that indices of warming-induced stress tolerance may provide a critical new tool for quantitative assessments of endangerment due to anthropogenic climate change across diverse species.