Estimating the benefits of plasticity in ectotherm heat tolerance under natural thermal variability
Estimating the benefits of plasticity in ectotherm heat tolerance under natural thermal variability
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DOI：
10.1111/1365-2435.12874
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发表时间：
2017-08-01
影响因子：
5.2
通讯作者：
Stillman, Jonathon H.
中科院分区：
文献类型：
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作者：
Gunderson, Alex R.;Dillon, Michael E.;Stillman, Jonathon H.
1.可塑性是一个几乎无处不在的特点，热生理的变温生物。要理解可塑性在进化和生态学背景下的重要性，需要确定观察到的可塑性是否有益，如果有益，可塑性可以在多大程度上补偿环境变化（即可塑性是“完全的”还是“不完全的”）。使用特定地点的日温度记录跨越几十年，我们测试的“有益的驯化假说”，通过计算的天数预测超过耐热极限的103个陆生外温动物种群时，将观察到的分类特定的可塑性和可塑性被证实。我们发现，耐热可塑性可以减少预测的过热事件的数量，虽然这种影响是特定的分支与可塑性提供更大的好处，两栖动物比爬行动物或节肢动物。尽管有这些好处，但耐热塑性是不完整的;随着温度的升高，塑性不能防止过热风险的增加。具体来说，我们发现，平均最高温度每上升一度，平均而言，在一年中最热的月份里，预计过热的时间大约会增加一天。我们进行了一个大规模的分析，在何种程度上可塑性的耐热性降低的可能性，外温动物的经验超过他们的生理热极限的温度。我们的研究结果表明，耐热性的可塑性有利于外温动物，但是，与以前的研究一致，这些好处不足以为全球气候变化提供完全的补偿。
1. Plasticity is a near-ubiquitous feature of the thermal physiology of ectothermic organisms. Understanding the significance of plasticity in evolutionary and ecological contexts requires determining whether observed plasticity is beneficial, and, if so, to what extent plasticity can compensate for environmental change (i.e. is plasticity 'complete' or 'incomplete').2. Using site-specific daily temperature records spanning several decades, we test the 'beneficial acclimation hypothesis' by calculating the number of days predicted to exceed the heat tolerance limits of 103 terrestrial ectotherm populations when incorporating observed taxon-specific plasticity and when plasticity is ignored.3. We find that heat tolerance plasticity can reduce the predicted number of overheating events, although the effects are clade specific with plasticity providing greater benefits to amphibians than to reptiles or arthropods. Despite these benefits, heat tolerance plasticity is incomplete; as temperatures rise, plasticity cannot prevent an increase in the risk of overheating. Specifically, we find that a one degree increase in mean maximum temperature leads to approximately one additional day of predicted overheating during the warmest months of the year, on average.4. We conducted a broad-scale analysis of the degree to which plasticity in heat tolerance reduces the probability that ectotherms experience temperatures beyond their physiological heat limits. Our results indicate that plasticity in heat tolerance benefits ectotherms, but, consistent with previous studies, those benefits are inadequate to provide complete compensation for global climate change.