Table 4.

Statistical results of spatial predictors based on the GAM model.

Factor	Variables	Chi.sq/ Estimate	P Value
Environmental	Elevation	99.618 a	0.000 ***
	Change of forest	13.747 a	0.010 *
	Change of grassland	42.210 a	0.000 ***
Meteorological	Mean temperature	72.594 a	0.000 ***
	Relative humidity	87.193 a	0.000 ***
	Precipitation	4.322 a	0.262
Socioeconomic	Population	4.615 × 10−5 b	0.000 ***
	GDP	4.322 × 10−5 b	0.054 †
	Urban accessibility	−1.195 × 10−3 b	0.038 *

Note: *** P < 0.001; * P < 0.05, ^† P < 0.1. ^a Chi.sq (chi-squared Test), ^b estimate.