Distinct Odonata assemblage variations in lentic reservoirs in Slovakia (Central Europe)

The effects of various aquatic habitats on the abundance, species richness, diversity and taxonomic distinctness of Odonata were studied. The impact of environmental factors and living conditions in lentic habitats were expressed by the composition of coenoses, on the evaluation we used the Dragonfly Biotic Index. The positive effects of habitat heterogeneity on biodiversity are well known, but it is not clear how the diversity of studied and ecologically important taxa, such as odonates, may vary in different water reservoirs. We investigated how Odonata community metrics (composition, abundance, diversity and environmental compatibility) differ in lentic water: ponds, fishponds, excavation of mineral material and in marshlands, where biodiversity plays an important role. Using an entomological mesh, we took samples in the south-western part of Slovakia in six geo-morphological units at 54 study sites during four years. This study detected distinct odonates assemblage variations among habitats and heterogeneity among gradients. Wide ranges of microhabitats with different environmental properties create appropriate conditions for living span of them. Surprisingly, the highest species richness was recorded in the excavation of mineral materials habitats. Stagnicolous Odonata species correlated (CCA) with the habitats of excavation of mineral material and marshlands; showed links to the littoral vegetation and dense vegetation cover. While the euryecious species have been linked to the ponds and fishponds; and correlated with the water body size. It seems to be degraded habitats are not so much suitable for rare and endangered species, but to preserve the biological value of the environment and for the existence of the high abundance and species richness of odonates.