Data from: Resolving biological impacts of multiple heat waves: interaction of hot and recovery days

Heat waves are increasing with global warming and have more dramatic biological effects on organisms in natural and agricultural ecosystems than mean temperature increase. However, predicting the impact of future heat waves on organisms and ecosystems is challenging because we still have a limited understanding of how the different components that characterize heat waves interact. Here we take an experimental approach to examine the individual and combine consequences of two important features that characterize heat waves: duration of successive hot days and recovery days between two hot spells. Specifically we exposed individuals of a global agricultural pest, the aphid Sitobion avenae to different heat wave scenarios by factorially manipulating the number of extreme hot days vs. normal days and altered which period individuals experienced first in their life cycle. We found that effects of heat waves were driven by a delicate balance of damage during hot periods vs. repair during normal periods. Increasing the duration of hot days in heat waves had a negative effect on various demographic rates and life-time fitness of individuals, but magnitude of this effect was typically contingent on the temporal clustering of hot periods. Importantly, this interaction effect indicates that changes in the temporal distribution of extreme hot vs. normal days can strongly alter the performance of organisms and dynamics of populations even when the total number of hot days during a given period remains unchanged. Together, these results emphasize the importance of accounting for the temporal distribution and quantitative patterns of extreme temperature events for predicting their consequences of natural and agricultural ecosystems.

随着全球变暖，热浪发生频次持续升高，其对自然与农业生态系统中生物的影响效应，较平均气温上升更为剧烈。然而，预测未来热浪对生物及生态系统的作用仍极具挑战，因我们对热浪各特征组分间的相互作用机制认知仍较为有限。本研究采用实验手段，探究热浪的两项核心特征的单一及联合效应：连续热天时长与两次热浪间隔的恢复期。具体而言，我们通过析因设计操控极端热天与正常天数的占比，并调整个体在生命周期中首次经历的温度时段，将全球性农业害虫麦长管蚜（Sitobion avenae）暴露于不同热浪情景中。研究结果显示，热浪的效应取决于热期损伤与常温期修复间的微妙平衡。延长热浪中的热天时长，会对个体的多项种群统计指标及终生适合度产生负面影响，但该效应的强度通常依赖于热期的时间聚集特征。尤为关键的是，这种交互效应表明：即便给定时段内的总热天数量保持不变，极端热天与正常天的时间分布变化，也会显著改变生物的种群表现与种群动态。综上，本研究结果强调，在预测极端温度事件对自然与农业生态系统的影响时，需充分考虑其时间分布与量化模式。