Mediterranean temporary ponds

Mediterranean temporary ponds are shallow ponds in the Mediterranean climate region that undergo a periodic cycle of flooding and drought. The flooding is mainly determined by the meteorology of the area. Flooding is annual and can be intermittent or seasonal. Most of these ponds are flooded in winter and spring when it rains (and sometimes in autumn) and they are dry in the warmest months of the summer when rains are scarce. The length of the hydroperiod (i.e. the period of time that a pond is inundated) depends on the meteorology. However, it is long enough for an aquatic community to form that is specific to these systems.

The periodic cycle of flooding and drought determines the flora and fauna of Mediterranean temporary ponds because the species that live in them must adapt to the changes. Both terrestrial and aquatic organisms must have strategies to survive during the dry period: they can move to permanent water or they can survive the dry phase in the pond sediment: as seeds, as drought-resistant cysts or eggs, or as juveniles and adults. For this reason, Mediterranean temporary ponds have high biodiversity and singularity. Therefore, the European Union considers these habitats a priority to protect and preserve within the European Habitat Directive.

Unfortunately, many Mediterranean ponds are destroyed, transformed or disappearing because of human activities. In recent decades, there has been continuing loss of these habitats worldwide. The main problem is their limited visibility (small size and ephemeral nature), which leads to a lack of recognition of their values and functions. Moreover, the small size of these ponds allows people to transform and modify them very easily.

The major threats of Mediterranean temporary ponds are over-extraction of water and draining, total and partial silting of the pond, excessive grazing or high frequentation, together with climate change. For this reason, it is urgent to increase our knowledge about Mediterranean temporary ponds and to raise awareness of the importance of the conservation and restoration (if necessary) of these ponds in our country.