Poore C L, Ibarra-Garibay E J, Toth A L, Riddell E A
Department of Ecology, Evolution, and Organismal Biology, Iowa State University, 2200 Osborn Drive, Ames, IA 50010, USA.
Department of Biology, University of North Carolina, Chapel Hill, NC 27514, USA.
Proc Biol Sci. 2025 Jan;292(2038):20242216. doi: 10.1098/rspb.2024.2216. Epub 2025 Jan 15.
Indices of climate vulnerability are used to predict species' vulnerability to climate change based on intrinsic physiological traits, such as thermal tolerance, thermal sensitivity and thermal acclimation, but rarely is the consistency among indices evaluated simultaneously. We compared the thermal physiology of queen bumblebees between a species experiencing local declines () and a species exhibiting continent-wide increases (). We conducted a multi-week acclimation experiment under simulated climate warming to measure critical thermal maximum (CT), critical thermal minimum (CT), the thermal sensitivity of metabolic rate and water loss rate and acclimation in each of these traits. We also measured survival throughout the experiment and after the thermal tolerance trials. Neither species acclimated to the temperature treatments by adjusting any physiological trait. We found conflicting patterns among indices of vulnerability within and between species. We also found that individuals with the highest CT exhibited the lowest survival following the thermal tolerance trial. Our study highlights inconsistent patterns across multiple indices of climate vulnerability within and between species, indicating that physiological studies measuring only one index of climate vulnerability may be limited in their ability to inform species' responses to environmental change.
气候脆弱性指标用于根据内在生理特征（如热耐受性、热敏感性和热适应性）预测物种对气候变化的脆弱性，但很少同时评估指标之间的一致性。我们比较了一个在当地数量下降的物种和一个在整个大陆数量增加的物种的蜂王的热生理学。我们在模拟气候变暖条件下进行了为期数周的驯化实验，以测量每个物种的临界热最大值（CTmax）、临界热最小值（CTmin）、代谢率和失水率的热敏感性以及这些特征的适应性。我们还在整个实验过程中以及耐热性试验后测量了存活率。两个物种都没有通过调整任何生理特征来适应温度处理。我们在物种内部和物种之间的脆弱性指标中发现了相互矛盾的模式。我们还发现，在耐热性试验后，CTmax最高的个体存活率最低。我们的研究突出了物种内部和物种之间多个气候脆弱性指标的不一致模式，表明仅测量一个气候脆弱性指标的生理学研究在为物种对环境变化的反应提供信息方面的能力可能有限。
