Spatio-temporal patterns of dragonfly occurrence on meadows in the national park Donau-Auen, Lower Austria
Wild Natascha, University of Vienna (AT)
Dispersal is a characteristic trait in Odonata. While dispersal behaviour of dragonflies and damselflies between waterbodies has generally received a great deal of attention, dispersal processes subjected to terrestrial habitats and hence, Odonate's use in the context of foraging activities, have previously only attracted limited interest. This study aimed to investigate the dispersal of dragonflies and damselflies to meadows used for foraging or as refuge. The primary focus was on assessing species-specific dispersal characteristics influencing the spatial distribution of species, species richness and community structure on meadows. Therefore, dragonflies and damselflies were sampled between May and September 2016 at 16 meadow and eight waterbody sites in the Donau-Auen National Park (DANP), Eastern Austria near Orth an der Donau. In total, 1.427 dragonflies were recorded, including 667 observed on meadows. Anisopterans were more likely to disperse long distances from waterbodies than zygopterans, and females showed proportionally higher abundances on meadows than at waterbodies. Species composition, species richness and occurrence of dragonflies were highly influenced by the distance meadows were situated away from waterbodies. Moreover, the results from this study demonstrated that occurrence of Odonata, species richness and the structure of species assemblages are associated with structural characteristics of forest margins adjacent to meadows. For most Odonata species, a positive relationship between heterogeneity in forest margin vegetation structure and occurrence could be found. This study provides important insight into odonate's utilization of meadows embedded in floodplain systems and provides some basis for potential conservation management considerations with the aim to protect terrestrial habitats of rare dragonflies.