Major flood disturbance alters river ecosystem evolution
Major flood disturbance alters river ecosystem evolution
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DOI：
10.1038/nclimate1665
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发表时间：
2013-02-01
影响因子：
30.7
通讯作者：
Brown, Lee E.
中科院分区：
文献类型：
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作者：
Milner, Alexander M.;Robertson, Anne L.;Brown, Lee E.
洪水是形成河道和洪泛区结构以及相关河岸和河流内群落的主要驱动力（1，2），随着世界许多地区气候变化，洪水的强度和规模正在增加（3，4）。然而，预测洪水将如何影响河道及其社区的气候变化是有限的，缺乏长期的洪水前基线数据集在不同的生物群。在这里，我们显示鲑鱼，大型无脊椎动物和小型底栖动物群落，监测了30年的系统发展，由于冰川退缩，显着修改了一个重大的降雨事件，造成重大的地貌变化的流通道。粉红鲑鱼，减少到洪水前产卵密度的十分之一，在两代内恢复。大型无脊椎动物群落结构显着不同的洪水后，一些先驱类群，这已成为当地灭绝，prononized，而一些后来的殖民者被淘汰。大型无脊椎动物的演替轨迹被重置为15年前的群落结构。小型底栖动物的丰度迅速恢复，丰富度增加洪水后，一些以前未记录的类群殖民。生物恢复是独立的地貌恢复。根据生物群的显著不同的反应表明，在应用一般水生生态系统理论和概念预测洪水事件时需要谨慎。
Floods, major formative drivers of channel and floodplain structure and associated riparian and in-stream communities(1,2), are increasing in intensity and magnitude with climate change in many regions of the world(3,4). However, predicting how floods will affect stream channels and their communities as climate changes is limited by a lack of long-term pre-flood baseline data sets across different organismal groups. Here we show salmon, macroinvertebrate and meiofauna communities, monitored for 30 years in a system evolving owing to glacier retreat, were modified significantly by a major rainfall event that caused substantial geomorphic change to the stream channel. Pink salmon, reduced to one-tenth of pre-flood spawner densities, recovered within two generations. Macroinvertebrate community structure was significantly different after the flood as some pioneer taxa, which had become locally extinct, recolonized whereas some later colonizers were eliminated. The trajectory of the macroinvertebrate succession was reset towards the community structure of 15 years earlier. Meiofaunal abundance recovered rapidly and richness increased post-flood with some previously unrecorded taxa colonizing. Biotic recovery was independent of geomorphological recovery. Markedly different responses according to the organismal group suggest caution is required when applying general aquatic ecosystem theories and concepts to predict flood events.