Britta Uhl

Bridgie.is[at]gmx.de


Functional diversity of Microlepidopterans along environmental gradients in the reserve Pineta san Vitale (Italy)

As a part of the National Park “Parco regionale del Delta del Po” the coastal forest Pineta san Vitale near Ravenna (Italy) is one of the few remaining natural areas at the Adriatic coast of Italy, which is otherwise strongly influenced by human activities. Situated in the midst of one of the world’s biodiversity hotspots (viz. the Mediterranean region) and despite its relatively high legal protection status, this area is affected by different anthropogenically driven influences like industrial pollution caused by the neighboring harbor of Ravenna and subsidence induced soil salinization. These different anthropogenic influences in combination with the longitudinal position of the park along the coastline, with the industry in the south and more natural areas in the north, render Pineta san Vitale an exceptional study site for testing the impacts of anthropogenic influences on an isolated nature reserve, its environmental quality and its species.

In this study the large group of “Microlepidoptera” was analyzed along the two different gradients of anthropogenic influence – industrial pollution, measured by the distance to industrial plants, and soil salinization. For attracting and catching Microlepidoptera, automatic light traps were used at 16 different study sites in downy oak forest habitats all over the Park. Altogether, about 6800 moth individuals were caught and mounted. 6085 of them could be determined and assigned to at last 157 species from 25 families. For 147 species, data on the ecology like host plant relationships and feeding behavior were available from published literature. On this basis, the impacts of industry and soil salinization on species diversity, richness and composition, as well as on functional diversity and composition were tested.

The distance-to-industry gradient significantly influences species composition, has an effect on species richness and species abundances, and leads to a significant decrease of functional diversity and functional richness. In particular, Quercus-feeding species were decreasing significantly with declining distance, whereas species with larvae feeding on grasses gained more prevalence. For the soil salinization gradient also an influence on species composition was observable, but was much weaker than for the distance-to-industry gradient. Species richness, however, first declines with increasing soil salinization but then increases again at highest salinization values. Functional diversity is only declining by trend, although some species groups like those feeding on Quercus are declining significantly like for the distance gradient before.

To sum up, both tested ecological gradients have strong influence on the local microlepidopteran communities, though a community is always also influenced by other factors like surrounding landscape areas and the sites’ habitat structure itself. The anthropogenic influences on Pineta san Vitale are so not only visible in the vegetation structure, but also at higher trophic layers.

Diploma Thesis in Cooperation with Julius-Maximilians-Universität Würzburg (Germany); MSc course "Biology"

Supervisor: Dr. Brigitte Fiala, Julius-Maximilians-Universität Würzburg
Co-supervisor: Univ.-Prof. Mag. Dr. Konrad Fiedler; University of Vienna