Effects of climate change on the distribution of hoverfly species (Diptera: Syrphidae) in Southeast Europe

Climate change presents a serious threat to global biodiversity. Loss of pollinators in particular has major implications, with extirpation of these species potentially leading to severe losses in agriculture and, thus, economic losses. In this study, we forecast the effects of climate change on the distribution of hoverflies in Southeast Europe using species distribution modelling and climate change scenarios for two time-periods. For 2041-2060, 19 analysed species were predicted to increase their areas of occupancy, with the other 25 losing some of their ranges. For 2061-2080, 55% of species were predicted to increase their area of occupancy, while 45% were predicted to experience range decline. In general, range size changes for most species were below 20%, indicating a relatively high resilience of hoverflies to climate change when only environmental variables are considered. Additionally, range-restricted species are not predicted to lose more area proportionally to widespread species. Based on our results, two distributional trends can be established: the predicted gain of species in alpine regions, and future loss of species from lowland areas. Considering that the loss of pollinators from present lowland agricultural areas is predicted and that habitat degradation presents a threat to possible range expansion of hoverflies in the future, developing conservation management strategy for the preservation of these species is crucial. This study represents an important step towards the assessment of the effects of climate changes on hoverflies and can be a valuable asset in creating future conservation plan, thus helping in mitigating potential consequences.