Mediterranean temporary ponds (habitat type 3170*) in the South Aegean Archipelago islands (Greece): filling the gaps

Abstract

Mediterranean temporary ponds (3170*, Directive 92/43/EEC) are scattered in the South Aegean islands (Greece). Their importance for biodiversity is great; they host plant and animal species depending exclusively or to a large extent on water, and form special habitats which act as "life refuges". At the same time, they support the agricultural activities of the local residents and provide multiple benefits. In this study, we focus on the identification, delineation and mapping of the Mediterranean temporary ponds, the description of the composition of their vegetation, their structure and functions, assessment of their conservation degree and recognition of the pressures they face. The 3170* habitat type was identified, recorded and studied in 42 locations, on 10 islands. Our results indicate that, in the South Aegean, despite the adverse climatic conditions, several small temporary ponds are preserved. They have a high degree of diversity in terms of their ecological, morphological and physico-chemical features. These are often natural wetlands with a high diversity of plant species, but in several cases, humans have artificially modified their abiotic, and hence biotic, characteristics. Most temporary ponds are altered under the pressure of long-term use of water, mainly in cultivations and grazing. Excavation, embankment and road openings bring about further degradation. In places undergoing tourist development, these risks increase. Strengthening their protection efforts, especially under the pressure of change in the climatic conditions, is essential for the conservation of Mediterranean temporary ponds.