Trichoptera populations in the water system of the river tiber in tuscany and emilia romagna (Italy)

Abstract

Investigations were carried out during the summer of 1992 at 32 sampling stations situated on 19 rivers and streams of the River Tiber watershed in Tuscany and Emilia; of these, 31 were located upstream and one downstream from the Montedoglio Dam. Water quality was good and there were no environmental alterations upstream in the sampled streams. The Trichoptera study identified 33 species and 2 subspecies, 7 of which were new records for the area. Taxa abundance was evaluated by grouping into classes the individuals collected by semi-quantitative sampling. Aquatic stages of Trichoptera, which had a wide range of habitat and trophic categories, were used as indicators of resource distribution along the longitudinal profile of the streams. The results concur with the «River Continuum» model. Because the reservoir affects the faunistic communities in the downstream reaches of the three immissaries, the Trichoptera population is typical of tracts of higher order water courses. © 1995 Taylor & Francis Group, LLC.