The influence of climate change on Primula Sect. Crystallophlomis in southwest China

Climate change significantly affects the distribution of high-altitude plant species, particularly within the Primula Sect. Crystallophlomis found in Southwest China. This clade is valued for its ornamental and medicinal properties. This study aims to evaluate the impact of climate change on the potential distribution of P. crystallophlomis to inform conservation and ecological research.

An optimized Maximum Entropy model (MaxEnt) was utilized to predict the suitable habitat areas of P. crystallophlomis under 9 scenarios, using 161 distribution records and 22 environmental variables. The model parameters were set to RM = 1.5 and FC = LQH, achieving a high prediction accuracy with an Area Under the Curve (AUC) value of 0.820.

The analysis identified key environmental factors influencing the suitable habitat of P. crystallophlomis, including annual precipitation (bio-12), temperature seasonality (bio-4), mean diurnal range (bio-2), and precipitation seasonality (bio-15). Under current climate conditions, the suitable habitats are primarily located in the eastern Qinghai-Tibet Plateau, Hengduan Mountains, and Yunnan-Guizhou Plateau, exhibiting significant fragmentation. Notable declines in potential habitat area were observed from the Last Glacial Maximum (LGM) to the Mid-Holocene (MH), with future projections indicating further reductions, particularly under the Shared Socioeconomic Pathways 585 (SSP-585) scenario.

The suitable habitat of P. crystallophlomis, which tends to grow in consistently cold and moist environments, is expected to shrink, with a projected southward shift in its centroid. Global warming is anticipated to profoundly impact the suitable habitats of P. crystallophlomis, highlighting the urgent need for conservation efforts.