MEDIS: spatial data for Mediterranean islands

The intrinsic characteristics of islands make them unique for studying ecological and evolutionary dynamics. The Mediterranean Basin, a biodiversity hotspot, is rich in islands, hosting a significant global biodiversity proportion. Despite extensive research, a comprehensive spatial dataset for these islands is lacking. This study presents the first comprehensive spatial dataset of all Mediterranean islands larger than 0.01 km2, aiding ecological investigations and interdisciplinary research on economic, environmental, and social issues. The MEDIS spatial dataset offers detailed information on 36 geographic, climatic, ecological, and land-use variables, including island area, perimeter, isolation metrics, climatic space, terrain data, land cover, paleogeography, road networks, and geological information, providing a multifaceted view of each island's characteristics. The study encompasses 2212 islands in the Mediterranean Basin larger than 0.01 km2. The spatial grain varies, with datasets like CHELSA-BIOCLIM+ and EU-DEM providing high-resolution climatic and terrain data. The spatial dataset incorporates various datasets, each with its own timeframes, such as the Global Shoreline Vector from 2014 Landsat imagery and the WorldCover dataset from 2021. Historical data like the Paleocoastlines GIS dataset offer insights into island configurations during the Last Glacial Maximum. While not focusing on specific taxa, the study lays the foundation for comprehensive research on Mediterranean islands, facilitating comparisons and investigations into the distribution of native, endemic, or alien species. The level of measurement is extensive, encompassing a wide range of variables and providing polygonal features rather than centroids' coordinates.