The accelerating rate of global climate change at higher elevations and latitudes is increasing the potential for extreme climatic events. Here, a knowledge gap exists in how the order of exposure to, and duration of droughts and heatwaves affect their cumulative impact on aquatic communities. We tested experimentally for the legacy effects of simultaneous vs. sequential exposures to drought and heatwave on sediment‐dwelling algal communities (epipelon) from small fishless alpine lakes. In both simultaneous, and sequential exposure treatments involving drought followed by a heatwave, the negative effect of drought masked the effects of warming on chlorophyll‐inferred algal biomass and taxonomic composition. Reversal of order of exposure (i.e., heatwave followed by drought) lowered their cumulative effect on community structure. These findings highlight the potential for drought events to dominate over heatwaves in altering shallow littoral ecosystems at high elevations under a rapidly warming climate.

中文翻译：

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干旱和热浪对高山围生植物群落的解开影响：一项中宇宙实验


全球气候变化在高海拔和纬度地区的加速正在增加极端气候事件的可能性。在这里，干旱和热浪的暴露顺序和持续时间如何影响它们对水生生物群落的累积影响存在知识差距。我们通过实验测试了同时与连续暴露于干旱和热浪对来自小型无鱼高山湖泊的沉积物栖息藻类群落 （epipelon） 的遗留影响。在涉及干旱和热浪的同时和连续暴露处理中，干旱的负面影响掩盖了变暖对叶绿素推断的藻类生物量和分类组成的影响。暴露顺序的颠倒（即热浪后干旱）降低了它们对群落结构的累积影响。这些发现强调了在气候迅速变暖的情况下，干旱事件在改变高海拔浅层沿海生态系统方面主导热浪的可能性。