Improving species distribution models to improve species conservation: a case study on the endemic species Viola bertolonii Pio

Viola bertolonii is an endemic species restricted to the ophiolitic rocks of the Voltri Group (Liguria, Italy). To assess the potential impact of climate change on its future distribution, we carried out species distribution models (SDMs) using the MaxEnt algorithm. Occurrence data were obtained from Wikiplantbase Liguria and combined with four bioclimatic variables (bio1, bio6, bio12, bio15). We considered two global circulation models (IPSL-CM6A-LR and GFDL-ESM4) and two emission scenarios, the SSP370 and SSP585 scenarios, for the 2011–2040 period. Species occurrence was downloaded by iNaturalist, Climatic data were downloaded from CHELSA V2.1 dataset. Spatial predictions were spatially constrained to the ophiolitic extent of the Voltri Group, in accordance with the species’ ecological requirements (Figure 3 and Figure 4). The models project a potential shift in habitat suitability toward the northwestern part of the Voltri Group, likely due to increasing temperature in that area. However, a general expansion of suitable areas is predicted. These results raise questions about other potential limiting factors for the species’ current distribution such as competition with other species or land uses. Incorporating additional environmental variables, such as land use, will help to improve the accuracy of these models.