We compared the effects of recent shifts of northern range boundaries of odonates adapted to either lentic (standing water) or lotic (running water) habitats in Europe. Lentic species are thought to have a higher dispersal propensity than lotic species because of the lower spatial and temporal persistence of lentic habitats on average. Hence, we expected shifts in the range boundaries particularly of lentic species.
Our analyses are based on odonate distribution maps from two field guides that present the European ranges of dragonflies and damselflies in 1988 and 2006. We categorized species according to their preference for lentic or lotic habitats, and then assigned each species to a southern or a northern group according to the centre of its distribution. Shifts in northern range boundaries were calculated as the average distance between the 10 northernmost grid cells in 1988 and 2006. Range boundary shifts were also analysed with regard to prevalence, phenology, body size and wing size.
Lentic species of the southern group expanded their range boundaries on average 115?km northwards per decade, whereas lotic species of the southern group on average did not change their range boundaries. Northern lentic and lotic species showed no consistent trends in their changes in range boundaries. These results did not qualitatively change when we considered the effects of phylogeny, phenology, body size and wing size.
Our results support the hypothesis that species adapted to lentic habitats, which are assumed to be less persistent in time and space, disperse better than lotic species.|