Mediterranean temporary wetlands: biodiversity, functioning and conservation

The aims of this research were to: i) assess plant biodiversity in Sardinian Mediterranean temporary wetlands (TWs); ii) identify key environmental factors affecting it and possible interactions with other taxonomic groups, and iii) define conservation issues. Plant biodiversity was evaluated at different spatial scale. The application of a fine-scale zonation sampling approach allowed identifying different assemblages “within TW”, with different floristic, structural, and sintaxonomical features at each site in the same relative position. Three belts were recognized: central, intermediate and outer characterised by different water depth and flooding period. Comparisons at scale of the entire temporary TW pointed out differences due to substratum, elevation and size. At temporal scale differences between assemblages were significant only in the same environmental conditions (e.g. TWs located at the same site). While vegetation pattern was mainly driven by “within TW” effect, investigation on soil pattern pointed out that it is mainly due to “a site effect”. Significant positive relationships were found between plant and crustacean assemblages, not only in terms of community structure but also at composition level. Conservation relevance was related to the presence of habitats of Community interest and listed species. Intraspecific variability and conservation status were assessed to some species strongly dependent to this habitat type (e.g. Isoetes histrix).