Session

The “LIFE18 NAT/IT/000803 DRYLANDS” project aims at restoring continental acidic dry grasslands in eight Natura 2000 sites in the western Po Plain. A dynamic approach was applied to restore the structure of the target habitats, aimed to preserve a mosaic of pioneer, intermediate and mature stands. This takes into account the processes driving their formation and results in a higher biodiversity. The main concrete actions carried out included: sod cutting and topsoil inversion, mowing of herbs with subsequent removal, cutting of native and invasive woody species, and planting of typical herb species. The effectiveness of the actions was assessed by the monitoring of (1) vegetation structure as well as the diversity of (2) vascular plants, (3) bryophytes, (4) lichens, (5) carabid beetles, and (6) butterflies. This was performed within circular plots (3 m radius) established within the target habitat patches with an area-dependent sampling effort, in Spring 2020-2021 for the ex-ante and in Spring 2023 for the ex-post. Overall, 64 plots were monitored. Our results showed a clear improvement of habitat structure in the target grasslands, which recovered their open structure. After removal of woody plants and interventions on soil, the cover of therophytes and bryophytes increased significantly, whereas lichens did not show such short-term dynamics. The number of typical species for plants and the overall number of species for bryophytes also increased. Locally, also non-native annual plants were favoured, but they maintained low cover values. The overall species richness of carabid beetles and butterflies remained about the same, but the number of sampled individuals more than doubled, and the number of species sampled per patch also increased; especially carabids also showed an increase in species typical of open habitats. The results confirmed the appropriateness of a multitaxon approach to evaluate the effectiveness of grasslands restoration, with the different taxa providing different perspectives on its effects. The monitoring should continue also in future years, to better elucidate the effectiveness of the method on the long term and any critical issues linked to the different responses across different taxa.