乌苏里江洪泛湿地蜻蜓目幼虫对水文连通阻断的生态响应

大型底栖动物的群落组成完整性能够指示和预测水生态环境的健康程度和变化趋势,已经在大量研究中得到验证。然而,群落水平的全部样品采集过程的复杂性并不利于它们的便捷应用。蜻蜓目幼虫是大型底栖动物中相对易于捕捉和识别的类群,并且拥有特别的两栖生命周期,它们的多样性特征以及对水体性质变化的敏感反应,使其成为湿地生态系统中非常广泛且适宜的指示生物。本研究通过比较乌苏里江人工堤坝内外两侧不同河段的河滨湿地中蜻蜓目幼虫的群落组成,分析堤坝阻隔对河滨湿地的生态影响,评估蜻蜓目幼虫对河滨湿地的环境指示特征。结果表明,随着乌苏里江由上游至下游,河滨湿地蜻蜓目幼虫的多样性愈加丰富;阻隔水文连通对蜻蜓目幼虫的生存繁育产生负面的作用,且越趋近下游,蜻蜓目幼虫受到人工堤坝的影响程度越显著;堤坝两侧不同物种的密度变化差异较小,主要区别在于直接与河流水文连通的样点多样性指数值的波动范围相对较大。

The ecological response of Odonata larvae to hydrologic connection blocking in riverside wetlands of the Wusuli River

The composition integrity of macrobenthos community can be used to indicate and predict the health and change trend of aquatic environment,as being widely verified in literature.However,the complexity of sampling at the community level retards their convenient application.Odonata larvae,with an extraordinary amphibious life cycle,are relatively easy to be sampled and recognized among the macrobenthos.The diversity of Odonata larvae and their sensitive reaction to changes of water properties make them a very broad and appropriate bio-indicator for wetlands.We analyzed the ecological impacts of the dyke barriers on riverside wetlands and evaluated the environmental indicator role of Odonata larvae on riverside wetlands by comparing the community composition of Odonata larvae in the riverside wetlands of different reaches on both sides of the artificial embankment of the Wusuli River.The results showed that the diversity of Odonata larvae in the riverside wetlands was increasing along the Wusuli River from the upstream to the downstream.Blocking hydrologic connection had a negative effect on the survival and breeding of Odonata larvae.The closer to the downstream,the more significantly the Odonata larvae were affected by artificial dykes.The density of different species on both sides of the dyke had limited variation,while the main difference existed in the relatively large fluctuation range of diversity index value in the sampling sites directly connected with the river hydrology.