A plan to conserve the last Sphagnum-dominated communities in the karst dolines of Castelluccio Plains (Central Apennines)

Castelluccio karst plains (Central Italy) host the only site with Sphagnum populations in Umbria: S. subsecundum at Pian Piccolo and S. platyphullum at Pian Grande of Castelluccio. According to Natura 2000 network, these communities are included in Habitat 7140. In S Europe they reach their southern distribution limits with consequent impoverishment of diagnostic species. Despite the habitat surfaces being extremely localized, such post-glacial relicts play an important role as an indicator of climate change. So far, these communities are still poorly investigated, and a detailed study on their phytosociological assessment and ecology is still missing yet essential to give the correct guidelines for their future protection and conservation. As a preliminary investigation, 36 relevés were made following hydrology-guided transects and the Braun-Blanquet method. As a result, three main vegetational aspects were detected: i) Caricion gracilis with Sphagnum in the wettest area; ii) ecotonal transition on more acidic and organic soil with Caricion nigrae within Sphagnum, Aulacomnium palustre and Polytrichum commune; iii) Nardo-Agrostion grassland in the driest conditions. The main pressures observed until now are: i) extremely dry conditions in August; ii) intensive mowing and iii) grazing of large livestock. The first factor leads to complete desiccation of Sphagnum for long periods of time; the second factor accelerates this process removing the protection given by vascular plants, which act like moisture traps and shade providers. Furthermore, intensive mowing often removes entire layers of Sphagnum. The third factor leads to heavy trampling, which destroys already low coverage patches of the rare peat moss genus in Central Italy. An evaluation of approaches to sustainable management of grasslands with the presence of Sphagnum spp., through different types of mowing techniques, is carried out to evaluate how these can affect the conservation of such an endangered Habitat.