Dry grassland diversity in the Italian Ligurian, Maritime and Cottian Alps: Report of the GrassPlot dataset IT_AD from the 20th EDGG Field Workshop

The 20th Field Workshop of the Eurasian Dry Grassland Group (EDGG) was held between 28th May and 6th June 2025 in the dry grasslands of the Ligurian, Maritime and Cottian Alps in Italy. Completing the series of sampling events in the dry grasslands of the Alpine arc, this Field Workshop collected data from the south-westernmost area of the Alps. The standardised EDGG sampling methodology was applied to collect data on vascular plants, bryophytes and lichens from dry grasslands and related open habitats, mainly belonging to Festuco-Brometea and Sedo-Scleranthetea communities, contributing to fill knowledge gaps in previously underrepresented regions. To provide a basis for future syntaxonomic revision of dry grassland vegetation, we sampled 137 10 m² plots with 50 of them nested in 25 EDGG Biodiversity Plots (nested plots of 0.0001 to 100 [1,000] m²). The sampling sites were distributed along a broad elevation gradient, ranging from 415 to 1890 m a.s.l., with a mean elevation of 1049 m a.s.l. Preliminary analyses indicate that vascular plant richness averaged 38.6 species in 10 m2, ranging from 8 to 70 species. This is a high value compared with previous EDGG Field Workshop reports from Alpine dry grasslands and may be related to the Mediterranean influence in the study region. The collected vegetation data, along with soil data, will be included in the GrassPlot database as dataset IT_AD. This will support further analysis based on standardised data, facilitating the observation of diversity patterns in both temporal and spatial scales and contributing to a better understanding of open habitats in the Palaearctic Region.