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 norm...随着全球变暖，热浪事件愈发频发，相较于平均气温升高，其对自然与农业生态系统中的生物个体所产生的生物学效应更为显著。然而，精准预测未来热浪对生物与生态系统的影响仍极具挑战，原因在于我们对构成热浪的各项特征组分之间的相互作用机制仍缺乏充分认知。本研究采用实验方法，探究构成热浪的两项关键特征各自及其联合作用所带来的效应：连续高温日时长与两次热浪事件之间的恢复日数。具体而言，本研究以全球性农业害虫——麦长管蚜（Sitobion avenae）为实验对象，通过析因设计操控极端高温日与正常日的占比，并调整实验个体在其生命周期中最先经历的时段，以此构建不同的热浪情景对蚜虫进行暴露处理。研究发现，热浪所产生的效应，取决于高温时段所造成的损伤与正常时段内机体修复之间的精妙平衡……