The increased northern range expansions of dragonflies (Odonata) in Sweden

Sammanfattning

As the global temperature increases for every year that passes, and losses in bodies of water continues to drive its inhabitants out of their established homes, it is to no surprise that dragonflies (Odonata) are increasingly shifting their ranges northward even in the northern regions of Sweden. This study investigates the expanding northern range of dragonflies in Sweden over the past two decades, using citizen science data from the Swedish Species Observation System; Artdatabanken, SLU (Swedish University of Agricultural Sciences). The analysis examines observational data from 2005 to 2025, focusing initially on 64 dragonfly species, to identify patterns in their northern range expansions. Using quantile regression analysis, the study analyses the median and upper 30-percentile of northbound reports. The results indicate that 64% of species with viable data had significant correlations with latitudinal shifts moving upwards, supporting the hypothesis of increasing northern range expansions. Although the findings confirm a notable increase in the average latitude of dragonflies, not all species exhibit parallel trends, with some showing unexpected declines due to a potential lack of knowledge. The implications of these findings highlight the potential for altered predator-prey dynamics and biodiversity impacts in both established and newly occupied habitats. Future studies should explore the underlying causes of these shifts, particularly in relation to climate change and habitat preferences, to better understand the choice between expansion over adaptation of dragonflies in their race against global warming.