Combining Niche Breadth to Predict the Current and Future Distribution of Leguminosae under Climate Change on the Qinghai-Xizang Plateau.

The Leguminosae family plays a significant role in life and serves as an important food crop. However, global warming poses a serious threat to the growth and potential distribution of Leguminosae species on the Qinghai-Xizang Plateau. In this study, we employed the MaxEnt model alongside ecological niche models (ENMtools) to predict the distribution of Leguminosae in the Qinghai-Xizang Plateau under various climate scenarios (RCP2.6, RCP6.0, RCP8.5) for both the present (Current) and future (2050s, 2070s). This analysis was conducted in conjunction with ecological niche principles. The results showed that: (1) The AUC values of the eight Leguminosae species were all greater than 0.9, indicating that the model had a good prediction accuracy. (2) The distribution of the eight Leguminosae species was primarily influenced by altitude. S. alopecuroides and C. korshinskii were found to be suitable for growth at lower altitudes (Approximate range 1600 ~ 2000 m). In contrast, A. mongholicus, G. uralensis, and M. ruthenica were suitable for growth at high altitudes (Approximate range 2300 ~ 2550 m). (3) The ecological niche of S. alopecuroides was found to be largest (B1 = 0.16, B2 = 0.92), whereas that of G. uralensis was smallest (B1 = 0.06, B2 = 0.87). Meanwhile, M. ruthenica exhibited the highest ecological niche overlap with M. sativa (D = 0.69, I = 0.92), followed by M. sativa and M. officinalis (D = 0.65, I = 0.88), and the lowest overlap was observed between M. sativa and S. salsula (D = 0.40, I = 0.67). Regarding range overlap, G. uralensis demonstrated a significant degree of overlap with most species, particularly with S. salsula, which had the highest overlap value (0.81). Conversely, S. salsula exhibited relatively low range overlap with most species, with G. uralensis and M. officinalis had the lowest range overlap (0.25). (4) Under future global warming climate scenarios, the suitable habitat for M. ruthenica is projected to decrease, while the suitable habitat for the other seven Leguminosae species is expected to increase to varying extents. This study can provide a reference for species conservation of Leguminosae in the Qinghai-Xizang Plateau and the planning of species conservation areas.