Isoeto-Nanojuncetea in Puglia (S-Italy): First phytosociological survey

Mediterranean temporary ponds (MTP) are considered among the most interesting habitats in the Mediterranean bioclimatic region due to the range of rare and threatened taxa they host. Their ephemeral vegetation presents a particular floristic composition, adapted to unstable ecological conditions due to the alternation between flood and drought. Indeed, these amphibian plant species are established on soils flooded in winter and dry since early summer. The water depth and inundation period determine the plant communities distribution. The vegetation can be referred to the class Isoeto-Nanojuncetea, that has a wide distribution and is represented in the study area by two orders: Isoetetalia, Mediterranean and W-European, with spring and early summer bloom, and Nanocyperetalia, C-European, with late summer and autumn bloom. This study describes for the first time the Isoeto-Nanojuncetea plant communities in Puglia Region, in SE-Italy, where the class distribution was unknown up to now. The here adopted syntaxonomical scheme is consistent with numerical analysis, resulting in homogenous floristic and ecological communities that correspond to syntaxa at association level. The phytosociological approach to the interpretation and management of vegetation and biodiversity has been recently revived by the habitat-type classification adopted by the European 92/43/EEC "Habitat" Directive in its Annex I. The here considered plant communities belong to the priority habitat "3170∗ Mediterranean temporary ponds". Aiming to typify them, 170 surveys were carried out in temporary pools over a wide area resulting from a detailed survey that took into account the whole Puglia territory. These complexes of vegetation are very sensitive to the environmental and anthropic disturbance, so they might be good bioindicators with high value for habitat monitoring and conservation.