3.3 Patterns of endemic species richness
Endemic (n = 67) species were found in 1430 grids, approximately 28.27% of all species. Endemic species richness in each grid ranged from 0–33 (mean: 5.75 ± 6.54 SD) species (Figure 1c; Table S5). The distribution of endemic species is mainly concentrated in the Hengduan Mountains and the surrounding areas. However, their distribution in the north is rare, and only a few endemic species have adapted to high-latitude environments.
Unlike all species and non-endemic species, when a single factor acted, TES and ART had the highest effect on endemic species richness (Figure 2e, f; Table S6).
Finally, regarding the relationship between the distribution pattern of endemic species richness and predictor sets, the best prediction model contained seven variables (EW1+EW2+CS1+CS2+HH1+HE1+HE2). OLS and SAR explained 65% and 53% of the total variation. The importance of the variables in explaining the endemic species richness pattern differed significantly between the two regression models (Table 1). In OLS, CS1 dominates overwhelmingly and is positively correlated with CS2. However, HH1 and CS1 were equally important and negatively correlated with CS2 in SAR. In variance partitioning, 65.58% of the variance was explained by the four predictor sets. The largest variation in endemic species richness was the total effect of the climatic seasonal predictor set, explaining 45.89% of the variation. The habitat heterogeneity set and energy-water predictor sets explained 32.44% and 15.14% of the variation in the endemic species richness pattern, respectively. The human factor predictor set explained the lowest variance (6.03%) (Figure 3a, d; Table S7).