Abstract:
Studies of ectotherm responses to heat extremes often rely on assessing absolute critical limits for heat coma or death (CTmax), however, such single parameter metrics ignore the importance of stress exposure duration. Furthermore, population persistence may be affected at temperatures considerably below CTmax through decreased reproductive output. Here we investigate the relationship between tolerance duration and severity of heat stress across three ecologically relevant life-history traits (productivity, coma and mortality) using the global agricultural pest Drosophila suzukii. For the first time, we show that for sublethal reproductive traits, tolerance duration decreases exponentially with increasing temperature (R2 > 0.97), thereby extending the Thermal Death Time framework recently developed for mortality and coma. Using field micro-environmental temperatures, we show how thermal stress can lead to considerable reproductive loss at temperatures with limited heat mortality highlighting the importance of including limits to reproductive performance in ecological studies of heat stress vulnerability.
摘要:
对极端高温的外热反应的研究通常依赖于评估热昏迷或死亡的绝对临界极限(CTmax),然而,这种单一参数度量忽略了压力暴露持续时间的重要性。此外,在CTmax以下的温度下,通过减少生殖输出,可能会影响种群的持久性。在这里,我们调查了三个生态相关的生活史特征(生产力,昏迷和死亡率)使用全球农业害虫果蝇。第一次,我们表明,对于亚致死的生殖特征,公差持续时间随温度升高呈指数下降(R2>0.97),从而扩展了最近针对死亡率和昏迷而开发的热死亡时间框架。利用现场微环境温度,我们展示了在热死亡率有限的温度下,热应激如何导致相当大的生殖损失,突出了在热应激脆弱性的生态学研究中包括对生殖性能的限制的重要性。