Quanto sono differenti i boschi di conifere? Confronto fra le comunità di Lepidotteri notturni di abetine e pinete in Calabria

Abstract

Abstract: The main coniferous forests of Calabria (Italy) are certainly the Calabrian black pine (Pinus nigra calabrica) forests of the Sila massif and the silver fir (Abies alba) forests of the Serre Vibonesi. Despite these woodlands are of great importance both economically and from a conservationist point of view, biodiversity of moth has been investigated in a non occasional way only for the Sila Calabrian black pine forests, while the silver fir woods of the Serre have been only recently the subject of studies. Apart from increasing the knowledge on the biodiversity of the nocturnal Lepidoptera hosted by Calabrian coniferous forests, the aim of this study was to compare the sampled communities to find out the main differences and their causes. The sampling was conducted in 9 sites for each forest type, distributed so as to cover the different development stages of ecological succession, from open areas to mature woodlands. A light trap was monthly placed at each site from May to November 2015, for a total of 126 nights/trap. The two communities showed low similarity indices (Classic Jaccard = 0.396; Sorensen Classic = 0.568), due both to the component trophically linked to the dominant forest species and to the component linked to the herbaceous layer. In fact, the dominant species in the Calabrian black pine wood and in the silver fir wood (Thera firmata and Macaria liturata, respectively) are absent or only occasionally present in the other forest type, and the community linked to the herbaceous layer is much better represented in the Calabrian black pine forest (29.7% of the total) than in the silver fir forest (14.9%). The arrangement of the Sila landscape, where Calabrian black pine forests alternate with pastures, shrubs and cultivated fields, seems to be the cause of the increased presence of species related to non-forest vegetation layer, while the micro-climatic conditions of the silver fir forest, more humid and temperate, favor the presence of a limited share of species trophically associated with herbaceous plants, which, however, have a high bio-geographical interest.