Odonates as indicators of the ecological integrity of the river corridor: Development and application of the Odonate River Index (ORI) in northern Italy
Odonates as indicators of the ecological integrity of the river corridor: Development and application of the Odonate River Index (ORI) in northern Italy
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DOI：
10.1016/j.ecolind.2015.09.022
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发表时间：
2016-02-01
影响因子：
6.9
通讯作者：
Surian, Nicola
中科院分区：
文献类型：
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作者：
Golfieri, Bruno;Hardersen, Soenke;Surian, Nicola
河流生态状况评估对于河流的适当管理和恢复至关重要。通常用于评估河流状况的生物指示物（即硅藻、水生大型植物、底栖大型无脊椎动物和鱼类）检测水质的变化，但对水系的另一个相关压力-水文形态退化并不特别敏感。此外，这些生物指示剂通常仅应用于流动通道。我们开发了一个新的多尺度指数，Odonate河指数（ORI），以评估整个走廊的冲积河流的条件。ORI是在奥地利提出的一个评估系统的基础上发展起来的，并以奥多内生境指数（OHI）为基础。被选为生物指示剂的河流走廊的生态完整性，因为这个分类群提供信息的条件下，他们的水生繁殖场所，以及周围的陆地区域，由于其两栖生命周期。我们使用了一个案例研究的18个河段，从意大利阿尔卑斯山的河流，其特点是不同的形态条件和水平的人类影响。在每个研究范围内，我们选择了四个网站，无论是lentic网站和lentic网站。蜻蜓调查包括成虫的实地观察，以及幼虫和蜕皮的收集。为了定义最佳的采样策略，我们比较了通过结合不同的采样方法获得的不同输入数据的ORI指标的结果：结合对成年人的观察和对分泌物的收集，获得了努力和穷尽性之间的最佳折衷。我们发现，ORI是一个强大的和可靠的工具，以评估在广泛的环境条件和河流形态的河流走廊的状态，特别适合检测水生和河岸植被的结构的水生形态退化和改变。我们确定了该指数适用性的两个限制因素：主河道的低水温（即年平均值低于10摄氏度）和没有或缺乏水生和河岸植被的河段。除了评估河流状况外，ORI还可用于监测河流恢复行动的效果。(C)2015爱思唯尔有限公司版权所有。
The assessment of the ecological conditions of rivers is crucial for their appropriate management and restoration. Bioindicators commonly used to evaluate the river status (i.e. diatoms, aquatic macrophytes, benthic macroinvertebrates and fish) detect alterations of water quality, but are not particularly sensitive to hydromorphological degradation, which is another relevant pressure in river systems. Furthermore, those bioindicators are usually applied only to flowing channels. We developed a new multimetric index, the Odonate River Index (ORI), to assess the conditions of the whole corridor in alluvial rivers. The ORI is a development of an evaluation system proposed in Austria, and based on the Odonate Habitat Index (OHI). Odonates were chosen as bioindicators for the ecological integrity of the river corridor, since this taxon provides information on the conditions of their aquatic breeding sites, as well as on the surrounding terrestrial areas, due to its amphibiotic life cycle. We used a case study of 18 reaches from six Italian Alpine rivers, characterized by different morphological conditions and level of human impact. Within each study reach, we selected four sites, both lotic and lentic sites. Dragonfly surveys consisted in field observation of adults, and collection of larvae and exuviae. To define the best sampling strategy, we compared the results of the ORI metrics obtained varying the input data by combining different sampling methods: the best compromise between effort and exhaustiveness was obtained coupling the observation of adults with the collection of exuviae. We found the ORI to be a robust and reliable tool to assess the status of the river corridor in a wide range of environmental conditions and river morphology, being particularly suitable to detect hydromorphological degradation and alterations of the structure of aquatic and riparian vegetation. We identified two limiting factors for the applicability of this index: low water temperatures of the main channel (i.e. mean annual value below 10 degrees C) and river reaches with no or scarce aquatic and riparian vegetation. In addition to the assessment of river conditions, the ORI could also be applied for monitoring the effects of river restoration actions. (C) 2015 Elsevier Ltd. All rights reserved.