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).