Prediction of Suitable Habitats for Tibetan Medicinal Gentiana Plants of Jieji- and Bangjian-Type Gentianas Based on the MaxEnt Model

The Gentianaceae family, particularly the genus Gentiana, is predominantly distributed across the Qinghai–Tibet Plateau and its adjacent regions. As a widely used traditional medicinal resource in Tibetan medicine, these plants possess diverse pharmacological activities, including heat-clearing, detoxification, antibacterial, antitumor, and immunomodulatory effects. Based on their medicinal properties and traditional use, Gentiana plants in Tibetan medicine are classified into two major groups: Bangjian-type and Jieji-type plants. In the context of intensifying climate change, understanding the responses of these two Tibetan medicinal plant groups to future climate scenarios is of great significance for the effective conservation and sustainable utilization of Gentiana resources. In this study, distribution data from 355 Bangjian-type Gentiana and 417 Jieji-type Gentiana medicinal plants, along with 12 selected key environmental variables, were used to predict their potential suitable habitats under three climate scenarios—SSP126 (low-carbon), SSP245 (medium-carbon), and SSP585 (high-carbon)—across the present and four future time periods, using the Maximum Entropy (MaxEnt) model. The average AUC values of the Bangjian-type and Jieji-type Gentiana models were 0.925 and 0.924, respectively, indicating high predictive reliability. Under current climatic conditions, the estimated suitable habitat areas for Bangjian-type and Jieji-type Gentiana plants are 208.86 × 104 km2 and 211.70 × 104 km2, respectively. The most suitable regions are primarily located in the Southeastern Qinghai–Tibet Plateau, with distribution centroids in Jiangda County, Chamdo, Xizang, China. Altitude was the most influential environmental factor shaping their distribution, followed by precipitation and temperature. In the future, climate change is expected to reduce the overall habitat of Jieji-type Gentiana, with only moderate expansion projected in Central China under the SSP126 scenario. In contrast, Bangjian-type Gentiana is projected to experience habitat expansion in most climate scenarios, with only minor contractions under SSP585. These findings highlight the potential shifts in the distribution of Gentiana resources under various climate scenarios and provide a scientific basis for developing conservation strategies for Tibetan medicinal plants in the face of climate change.