Temporary Ponds evolution patterns over three decades and ecological implications for micro- and macroscopic biodiversity

Temporary ponds (TP) are unusual habitats seasonally flooded, with a short aquatic phase. They are extremely vulnerable habitats, recognized as priority habitats for the Habitat directive. There have been many controversies regarding the importance of temporary ponds in the past; this presentation will define the parameters to understand why these ecosystems are so worthy of protection and the variations on the ecological status over three decades. Here, we aimed to evaluate both hydroperiod and biodiversity health status of the temporary ponds neglected for more than 30 years. In this study, conducted within “The Presidential Estate of Castelporziano", a protected area in Italy, 169 temporary and permanent ponds were taken into consideration. Over six months of samplings, we found that about 30% of TP surveyed in the 1990’s is now completely dry, although the bearings were taken during the wet season. Despite the premise, about 10% of the ponds were new generation, not existing during the last samplings; climate change is strong affecting the lifetime of temporary ponds, reducing the life of some and generating others. The large TP biodiversity was represented by Copepod, Cladocera, Dytiscidae for macroinvertebrates, and Gomphonema, Navicula, Nitzschia for diatoms. Although the minor abundances, Lepidurus spp. and Chirocephalus spp. show high frequencies through the surveyed ponds. These results represent a new database useful for further comparisons and discussions on the climate change effects on TPs.