Central European cities maintain substantial dragonfly species richness - a chance for biodiversity conservation?

This study investigates whether cities have the potential of hosting high species diversity of dragonflies (Odonata), a target group in freshwater conservation. We reviewed the dragonfly fauna of 30 cities in Central Europe and analysed their species richness compared to the regional species pools in the hinterlands, i.e. estimated the amount of regional diversity represented in cities. In particular, we examined the occurrence of species of conservation concern at the European scale. Results revealed that 92.6% of all 81 Central European dragonfly species occurred in cities, as well as 85.7% of 14 species of conservation concern. As expected, assemblages of city species were subsets of the regional species pool and city species richness increased with regional species numbers. Some cities hosted the complete regional species pool. Ten species of conservation concern established autochthonous populations and six of them, such as Aeshna viridis and Ophiogomphus cecilia, were abundant at least in single cities. We conclude that there is good potential for cities to host high dragonfly diversity and even to promote species of conservation concern. To exploit this potential we recommend city planners to focus on the needs of regionally characteristic species.