Odonates as indicators of the ecological integrity of the river corridor: Development and application of the Odonate River Index (ORI) in northern Italy

摘要: Abstract The assessment of the ecological conditions rivers is crucial for their appropriate management and restoration. Bioindicators commonly used to evaluate river status (i.e. diatoms, aquatic macrophytes, benthic macroinvertebrates fish) detect alterations water quality, but are not particularly sensitive hydromorphological degradation, which another relevant pressure in systems. Furthermore, those bioindicators usually applied only flowing channels. We developed a new multimetric index, Odonate River Index (ORI), assess whole corridor alluvial rivers. ORI development an evaluation system proposed Austria, based on Habitat (OHI). Odonates were chosen as integrity corridor, since this taxon provides information breeding sites, well surrounding terrestrial areas, due its amphibiotic life cycle. case study 18 reaches from six Italian Alpine rivers, characterized by different morphological level human impact. Within each reach, we selected four both lotic lentic sites. Dragonfly surveys consisted field observation adults, collection larvae exuviae. To define best sampling strategy, compared results metrics obtained varying input data combining methods: compromise between effort exhaustiveness was coupling adults with found be robust reliable tool wide range environmental morphology, being suitable degradation structure riparian vegetation. identified two limiting factors applicability index: low temperatures main channel mean annual value below 10 °C) no or scarce In addition conditions, could also monitoring effects restoration actions.