The future of tanner’s sumac (Rhus coriaria) in a warming world

This study applies a MaxEnt-based species distribution modelling framework to characterize the current climatically suitable habitat of Rhus coriaria across Türkiye and to project its potential redistribution under three Shared Socioeconomic Pathway scenarios (SSP1-2.6, SSP3-7.0, and SSP5-8.5) by 2100. A final set of 146 spatially thinned occurrence records and seven environmental variables (annual mean temperature (bio1), roughness index, temperature seasonality (bio4), topographic position index, precipitation seasonality (bio15), annual precipitation (bio12), and maximum temperature of the warmest month (bio5)) were retained following multicollinearity screening. The model demonstrated good predictive performance (mean test AUC = 0.811). Under current conditions, 214,672 km² (32.7% of Türkiye) was identified as climatically suitable. All three future scenarios project an increase in total suitable area at the national scale — reaching 345,063 km² under SSP1-2.6, 316,448 km² under SSP3-7.0, and 276,186 km² under SSP5-8.5 — driven by substantial northward expansion into the Black Sea Region. However, this national-scale gain masks a pronounced contraction of suitable habitat in the Mediterranean and Aegean regions, where the species currently attains its highest abundance and economic importance. These findings provide a spatially explicit, climate-informed evidence base for conservation prioritization and sustainable management planning for this ecologically and economically valuable species.