Stefan Schneeweihs

Effects of lateral connectivity of backwater systems on dragonfly communities in the Danube River National Park

The dragonfly fauna of river floodplains comprises species colonizing the whole spectrum of aquatic habitats ranging from isolated small water bodies to backwaters connected to the main river during most of the year. While some species appear to have specific requirements on water flow dynamics, other more generalist dragonflies are able to colonize a wide range of backwaters independent of differences in their lateral connectivity with the main river.
This study will analyse effects of lateral connectivity of backwaters on species richness and species composition of dragonflies in the Danube River floodplains east of Vienna (Danube River National Park). Dragonfly surveys will cover all backwater types ranging from completely isolated ones to backwaters connected to river Danube for most of the year. Additionally, the incidence of individual species will be related to potentially important intrinsic (e.g. dispersal ability, local abundance) and extrinsic factors (e.g. backwater connectivity, availability of oviposition sites). Due to their high conservation relevance, special emphasis will be placed on habitat requirements of rheophilic species (e.g. Gomphus vulgatissimus).

In co-operation with the National Park Donau-Auen.