Limited plasticity in thermally tolerant ectotherm populations: evidence for a trade-off
Limited plasticity in thermally tolerant ectotherm populations: evidence for a trade-off
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DOI：
10.1098/rspb.2021.0765
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发表时间：
2021-09-08
影响因子：
4.7
通讯作者：
Kelly, Morgan
中科院分区：
文献类型：
--
作者：
Barley, Jordanna M.;Cheng, Brian S.;Kelly, Morgan
由于气候变化，许多物种面临灭绝风险，迫切需要确定哪些物种的种群将最脆弱。可塑性的耐热性，其中包括驯化或硬化，发生时，事先暴露于较温暖的温度改变了生物体的上限热。热驯化的能力可以提供对变暖的保护，但以前的工作已经发现了一些可推广的模式来解释这种特性的变化。在这里，我们报告的结果，据我们所知，第一个荟萃分析，以检查物种内的变化，在热塑性，使用的结果从20项研究（19个物种），量化的热适应能力在78个种群。我们使用元回归来评估两个主要假设。气候变率假说预测，从更多的热变栖息地的人口将有更大的可塑性，而权衡假说预测，最低耐热性的人口将有最大的可塑性。我们的分析表明，强有力的支持权衡假设，因为人口具有更大的耐热性降低了可塑性。这些结果推进了我们对种群对气候变化敏感性变化的理解，并意味着具有最高耐热性的种群可能具有有限的表型可塑性来适应持续的气候变暖。
Many species face extinction risks owing to climate change, and there is an urgent need to identify which species' populations will be most vulnerable. Plasticity in heat tolerance, which includes acclimation or hardening, occurs when prior exposure to a warmer temperature changes an organism's upper thermal limit. The capacity for thermal acclimation could provide protection against warming, but prior work has found few generalizable patterns to explain variation in this trait. Here, we report the results of, to our knowledge, the first meta-analysis to examine within-species variation in thermal plasticity, using results from 20 studies (19 species) that quantified thermal acclimation capacities across 78 populations. We used meta-regression to evaluate two leading hypotheses. The climate variability hypothesis predicts that populations from more thermally variable habitats will have greater plasticity, while the trade-off hypothesis predicts that populations with the lowest heat tolerance will have the greatest plasticity. Our analysis indicates strong support for the trade-off hypothesis because populations with greater thermal tolerance had reduced plasticity. These results advance our understanding of variation in populations' susceptibility to climate change and imply that populations with the highest thermal tolerance may have limited phenotypic plasticity to adjust to ongoing climate warming.