Environmental niche modelling of the Chinese pond mussel invasion in Europe under climate change scenarios

In this paper, we modelled the Chinese pond mussel distribution in the European subcontinent under the recent climatic conditions and two climate change scenarios.  Using species records of Sinanodonta woodiana (Bivalvia: Unionidae) in Europe and a set of bioclimatic variables, we applied the maximum entropy approach provided by MaxEnt to build the species distribution models and investigate how each climatic variable affects the species distribution. We found that winter temperatures had the largest contribution to the species distribution in all three scenarios (recent, RCP 4.5, RCP 8.5). We applied the minimum training presence threshold, as a less stringent, and 10th percentile training presence threshold, as more stringent, to map the potential area of the species occurrence. The models show that the climatically optimal range, depicted by the stricter threshold, will be expanded eastwards under all three scenarios. At the same time, the area of minimally suitable environments, represented by the less stringent threshold, will be contracted in the future climate. The species distribution models highlight that the climatic conditions of the British Isles and the Azov-Kuban Lowland are the most suitable, among the uninvaded regions, for further S. woodiana invasion.