Limestone dissolution and temporary freshwater rockpools of the Maltese Islands

Abstract

Temporary freshwater rockpools form in rocky depressions which accumulate surface water long enough to permit the development of specific aquatic vegetation and animal communities. These habitats alternate between periods of flooding during the wet season and sustained drought during the dry season. These pools are very small in size compared with other temporary pools present in the Mediterranean region, with surface areas ranging from a few tens of square centimetres to a few square metres. The pools are colonised by specialist fauna and flora characterised by compressed life cycles. The principal determinants of the biological cycles within pools are the frequency and duration of hydroperiods, and the water-retention properties of the sediment layer. Both factors act as environmental filters, excluding generalist species from the pool habitat.