Exploring habitat complexity in Mediterranean ponds: physicochemical heterogeneity and macrophyte community variation in inland Sicily

Mediterranean ponds are small but valuable habitats, yet the relationships between environmental heterogeneity and vegetation remain poorly explored. We surveyed 10 sites in central Sicily, including permanent, semi-permanent and temporary ponds, recording 42 taxa and macrophyte communities in 31 vegetation units (i.e., plots) and measuring water and sediment variables for each plot. Environmental clustering and PCA distinguished three vegetation typologies mainly defined by nutrients and sediment organic matter with significant differences in species turnover, whereas alpha diversity varied only marginally across clusters. The presence of differentiated plant communities sustains a relatively high baseline richness, while environmental heterogeneity is associated with macrophyte turnover rather than changes in cluster-level diversity.