Small-scale pattern of bryoflora in Mediterranean temporary ponds: hints for monitoring

In the Mediterranean region temporary ponds are classified among the most biologically and biogeographically interesting ecosystems. Despite their important ecological functions in those fragile environments, bryophytes are neglected or undervalued in most monitoring and conservation actions. We studied the composition and the small-scale spatial zonation of bryophytes within Mediterranean temporary ponds, to identify indicator species useful to characterize the spatio-temporal variability observed, and suggest elements to carry out simple monitoring based on dominant life form and strategy. Bryophytes are distributed in concentric belts (outer, central, inner) according to their tolerance to floods: we observed a gradient from the outer belt, mainly composed by colonist and perennial such as Pottiaceae and Brachytheciaceae, to the more humid inner one where annual shuttle such as Ricciaceae dominate. We found significant species associated with belts, such as Tortella squarrosa in the outer belt, Fossombronia caespitiformis in the central belt and Riccia canaliculata in the inner belt. Bryophytes can be used as bioindicators of the state of conservation of Mediterranean temporary ponds: the presence of indicator species and the distribution of dominant life form/strategies in the different belts allow to monitor over time the changes in the flood level