Mediterranean high-mountain grasslands represent critical biodiversity hotspots, delivering essential ecosystem services. However, these valuable ecosystems are increasingly vulnerable to climate-induced stressors, particularly rising temperatures, and intensified drought conditions. Investigating how plant communities adapt across moisture gradients is essential to unravel ecological responses to escalating water stress and to effectively guide targeted conservation actions. Within the framework of the BIODIVERSA–PRESINMED project ("Preserving the singularity of Mediterranean high-mountain biodiversity hotspots: a Nature-based Solutions Approach"), we characterized plant community composition and ecological variability in Mediterranean mountain wet meadows, beginning our survey in the Quarto Santa Chiara Natural Reserve, situated in Maiella National Park, Central Apennines, Italy. This site comprises a mosaic of wet grassland habitats distributed along a natural gradient of soil moisture, offering an ideal setting to explore spatial variability in herbaceous communities shaped by hydrological conditions. Our fieldwork focuses on four plant communities representing different points along this gradient. In each community, we established three permanent areas, where vegetation is surveyed during the peak growing season using four nested 1×1 m plots per area. This sampling design provides the foundation for long-term monitoring of species composition and community dynamics across this environmental gradient, including future analyses of phenology and grazing pressure. This first research season represents an initial step toward building a comprehensive ecological profile of the area, which will be further developed in the coming seasons. In addition to describing floristic patterns across habitats, we aim to evaluate whether Ecological Indicator Values for Europe (EIVE) are aligned with this moisture gradient. Preliminary results suggest a clear differentiation in species composition and EIVEs among habitat types, with the occurrence of rare plant species for Italian Mediterranean mountains. Interestingly, we observe higher species richness in the drier communities and not in medium wet grasslands, pointing to potential shifts in ecological filtering.