Taxonomic and Functional Structure of Benthic and Terrestrial Invertebrates During Wet and Dry Phases of an Intermittent River Within Central Italy

ABSTRACT Temporary rivers and streams are characterized by flow cessation and support high biodiversity of both aquatic and terrestrial species. In this study, we analyzed biological and ecological traits of benthic invertebrates to assess the ecological resilience and resistance of an intermittent river in Central Italy. Moreover, we observed the community of terrestrial taxa that colonize dry riverbeds during summer months, and we examined the functional composition of taxa found. Despite observed variation in taxa, the functional composition of the macroinvertebrate community remained relatively constant during the different hydrological phases, likely due to the functional redundancy of the present taxa. Contrary to expectations, the moment of highest overall diversity was recorded during October, when the river was characterized by the presence of several isolated pools. We observed a total of 22 terrestrial taxa, of which 11 were exclusively recorded in the dry gravel beds and not in the adjacent riparian zones. Historically, monitoring of the ecological health of temporary rivers was undertaken during flowing conditions, but an increasing number of studies are demonstrating that it is also important to focus attention on isolated pools and on dry phases. In light of climate change, temporary rivers will increase, and it is becoming ever more urgent to know the ecological characteristics of these ecosystems in order to develop and apply specific conservation plans.