Seasonal and spatial patterns of macroinvertebrate assemblages and environmental conditions in Mediterranean temporary ponds in Greece

Abstract

Mediterranean temporary ponds in Greece have been neglected, and only recently has attention been drawn to their protection and conservation. In this study, the macroinvertebrate fauna of the Mediterranean temporary ponds of western Crete was examined for the first time. In particular, the seasonal and spatial patterns of macroinvertebrate communities were assessed along with the spatio-temporal variation of their environmental conditions and hydroperiod variation. Benthic fauna and abiotic (physicochemical, hydroperiod) data were monitored for 3 years (2006–2008). A total of 63 macroinvertebrate taxa belonging to 33 families were recorded, with Plea minutissima, Berosus affinis, Pericoma sp., Culex sp., Chironomidae and Cyprididae being the most abundant. Nutrient pollution was significant in the ponds situated near agricultural areas and could thus explain the poor species richness. NMDS showed a clear spatial and temporal distinction between lowland and upland sites. Heteroptera species were exclusively encountered in spring, while Coleoptera larvae and adults were present in all seasons, with adults being more abundant during winter. Ordination analysis revealed significant seasonal and inter-annual differences in macroinvertebrate assemblage structure, as confirmed by ANOSIM (R = 0.965, p = 0.001). Species richness was relatively lower compared to temporary ponds from other regions because of their isolated character, unpredictable hydroperiod and degraded water quality. This study highlights that these fragile ecosystems sustain a unique invertebrate fauna able to endure pond drying by several survival traits and therefore their conservation and protection is necessary.