Ensemble forecasting of Corbicula fluminea worldwide distribution: Projections of the impact of climate change

Global biodiversity is at risk owing to climate change, and freshwater ecosystems are expected to suffer the most. In recent years niche-based models (NBMs) have been used to predict species distribution and are an important tool for conservation and management of aquatic ecosystems. In this work, the current and future climatic suitability areas of the invasive species Corbicula fluminea, which has known adverse ecological and economic impacts, were investigated. The species distribution modelling was based on nine algorithms in BIOMOD2, summarized in an ensemble forecasting approach. To model the species distribution, eight climatic parameters related to temperature and precipitation variables were considered. Three time frames (current, 2050 and 2070) were modelled using four increasing CO2 emission scenarios. The performance of individual models was excellent according to the area under the receiver operating characteristic curve (AUC) and good to excellent according to true skill statistics (TSS). Annual mean temperature, minimum temperature of the coldest month and mean temperature of the coldest quarter were the most important variables predicting C. fluminea occurrence. Of the total continental area, 6.6% was predicted to be suitable for C. fluminea in current conditions. In the future, suitable area will increase from the current value of 6.6% to values from 9.4% to 12.6%, according to the 2050 projections and up to 12.7% in 2070 in high emission scenarios. Overall, the results indicate that climate change will favour the expansion of C. fluminea into new river basins, especially at higher latitudes, and that future climatic scenarios may double the suitable area for Corbicula fluminea.