Mediterranean farmland ponds as unique habitats for plant diversity across different pondscapes

Wetlands are among the world's most vulnerable ecosystems. Particularly in the Mediterranean region, farmland ponds are strongly influenced by the agricultural land use in their surroundings, though supporting unique biodiversity. This study aimed to highlight the patterns of farmland pond plant diversity across different pondscapes-networks of interconnected ponds within a landscape-and different spatial scales, from local (pond-scale) to landscape level (pondscape-scale), with the aim of informing conservation planning. We surveyed plant communities across 45 farmland ponds located in three pondscapes of Tuscany in central Italy, with different agricultural land-use extents. We tested species richness and composition differences using permutational analysis of variance. Species richness and plant community composition varied with the extent of agricultural land use in the pondscape. Pondscapes with the highest agricultural land use extent had lower aquatic plant species richness, with dominance of species adapted to anthropogenic disturbance. In contrast, the pondscape with the lowest agricultural land-use extent hosted a richer aquatic biodiversity, particularly of helophytes. We found that pond-specific features, possibly related to pond management, play a more significant role than landscape-scale features in shaping plant diversity. This underscores the importance of acting on individual ponds in addition to whole pondscapes for plant conservation purposes.