Ecological interplay between diatoms and plants in Mediterranean temporary ponds habitat

In the Mediterranean region, temporary ponds (MTPs) are priority habitats hosting rare and endemic species significantly threatened globally. This research represents the first characterization of diatom communities of MTPs in Central Italy, coupling phytosociological surveys and physical and chemical characterization of water and sediments. We selected 3 areas and 13 ponds with different levels of protection. A total of 89 diatom species and 52 plant species were recorded. No significant differences in taxonomic and functional α diversity were observed among sites. Water conductivity was significantly associated with taxonomic richness. Functional α diversity showed significant correlation with several environmental variables, including conductivity, pH, sediment density, dissolved oxygen. Both taxonomic and functional total β diversity and turnover differed significantly among sites, in particular between Foglino and Castelporziano sites. RDA analysis based on vegetation as variable showed that the measured environmental variables explained 51.45% of the diatom community variation, providing the first evidence of ecological correspondence between diatom and plant communities in MTPs. Our results underpin the potential role of diatoms as bioindicators in MTPs.