Invertebrate community dynamics and insect emergence in response to pool drying in a temporary river
Invertebrate community dynamics and insect emergence in response to pool drying in a temporary river
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DOI：
10.1111/fwb.12591
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发表时间：
2015-08-01
影响因子：
2.7
通讯作者：
Larned, Scott T.
中科院分区：
文献类型：
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作者：
Drummond, Laura R.;McIntosh, Angus R.;Larned, Scott T.
以前的研究无脊椎动物的水文断开流和干燥的反应集中在栖息地与长的水文周期（干燥后断开，即几个月到几年）。在这里，我们专注于短期水文周期（干后迅速断开，即小时到天）对河流无脊椎动物群落和昆虫出现的影响。我们使用自然冲刷池在冲积河流，以测量在5个月的干旱无脊椎底栖动物和昆虫出现的变化。冲刷池代表了水文周期的梯度（从断开到完全失水的时间）。我们持续监测水位和理化状况。在连接，断开和干燥期间，以1至7天的间隔对每个池底部的底栖无脊椎动物和从每个池表面出现的水生昆虫进行采样。我们利用水位数据将这些水池分为快速干燥和缓慢干燥的水文周期类。群落结构随着池塘的断开和干涸而改变。双翅目幼虫密度在连接期高于断开期，蜉蝣目和毛翅目幼虫密度在断开期高于连接期。分类群丰富度较高，在快速干燥比缓慢干燥池。Shannon-Wiener多样性增加，水位下降缓慢干燥池，但没有检测到的影响，水位对多样性的快速干燥池。随着冲刷池水位的降低，水生昆虫的总出现量增加。然而，羽化率（每天的个人）蜉蝣目和数量上占优势的属Deleatidium随着水位下降。有些水生昆虫在快干池中没有完成发育。底栖无脊椎动物，坚持在池中，直到完全干燥占主导地位的类群与抗干燥特性。
Previous studies of invertebrate responses to hydrological disconnection from the flow and drying have focussed on habitats with long hydroperiods (dry slowly after disconnection, i.e. months to years). We focus here on the effects of short hydroperiods (dry rapidly after disconnection, i.e. hours to days) on river invertebrate communities and insect emergence. We used natural scour pools in an alluvial river to measure changes in the invertebrate benthos and insect emergence during a 5-month drought. The scour pools represented a gradient of hydroperiods (time from disconnection to complete water loss). We monitored water level and physicochemical conditions continuously. Benthic invertebrates on the bottom of each pool and aquatic insects that emerged from the surface of each pool as aerial adults were sampled at 1- to 7-day intervals during connected, disconnected and dry periods. We used the data on water level to group the pools into quick-drying and slow-drying hydroperiod classes. Community structure changed as pools disconnected and dried. The densities of larval Diptera were higher in the connected period than in the disconnected period, while those of larval Ephemeroptera and Trichoptera pupae were higher in the disconnected period. Taxon richness was higher in quick-drying than in slow-drying pools. Shannon-Wiener diversity increased as water level decreased in slow-drying pools, but there was no detectable effect of water level on diversity in quick-drying pools. Total emergence of aquatic insects increased with decreasing water level in the scour pools. However, emergence rates (individuals per day) of Ephemeroptera and the numerically dominant genus Deleatidium decreased with declining water level. Some aquatic insects did not complete development in quick-drying pools. Benthic invertebrates that persisted in pools until complete drying were dominated by taxa with desiccation-resistance traits.