Climate change is causing frequent and large floods, creating a need for information regarding the impact of severe flood disturbances on stream invertebrates. We briefly describe the response of invertebrate assemblages to an extreme flood event in 2018 in the western Ehime Prefecture of Japan. We compared invertebrate data collected in past regional-scale surveys with those gathered by revisiting 27 study sites after the flood and examined the relationship between catchment characteristics and the invertebrate response across the study area. Heavy rainfall was recorded in the catchment of each study site during the flood (range 565–1081 mm). Stream invertebrates may be eliminated by the historical flood, although the degree was small compared with that in previous reports on the effects of severe flood disturbances (abundance − 19.1%, taxon richness − 9.0%), likely owing to the absence of severe bed disturbance. Our results imply that high primary productivity, possibly caused by low elevations and the development of farms, accelerated the recovery of invertebrates after the disturbance. They also suggest that assembling pre-disturbance data is the key to understanding the impact of extreme floods on stream invertebrates and managing stream ecosystems during climate change.

气候变化造成了频繁的大洪灾，因此需要有关严重洪灾干扰对河流无脊椎动物的影响的信息。我们简要描述了无脊椎动物种群对日本西部爱媛县2018年极端洪水事件的响应。我们将过去区域规模调查中收集的无脊椎动物数据与洪水后重新访问27个研究地点所收集的数据进行了比较，并研究了整个研究区域的流域特征与无脊椎动物响应之间的关系。在洪水期间，每个研究地点的流域记录到大雨（范围为565–1081 mm）。河流无脊椎动物可能会因历史洪水而被淘汰，尽管其程度与先前关于严重洪水扰动影响的报道相比程度较小（丰度-19.1％，分类单元丰富度-9.0％），这可能是由于没有严重的床铺干扰造成的。我们的结果表明，可能由低海拔和农场的发展引起的较高的初级生产力促进了扰动后无脊椎动物的恢复。他们还建议，收集扰动前数据是了解极端洪水对河流无脊椎动物的影响以及在气候变化期间管理河流生态系统的关键。