## 3 Results
### Vegetation Growth in Different Environments  
The fluctuations of LAI and GPP under various environmental conditions can be provided by the risk detector. Only factors with q values greater than 0.1 were further analyzed here. For LAI and GPP, the results of optimal discretization for some factors, such as humidity index and ETo, were different and presented separately. The values of LAI and GPP rose when precipitation increased from 355.04 to 511.4 mm (Figure 9a). When the precipitation ranged from 511.4 to 742.28 mm, the values of LAI and GPP remained stable. LAI values increased continuously as the humidity index rose from 0.35 to 0.53 (Figure 9b), and LAI values remained constant at 0.9 m\({}^{2}\) m\({}^{-2}\) when the humidity index was between 0.53 and 0.61. LAI continued to rise as the humidity index rose from 0.61 to 0.78, and it peaked at 1.42 m\({}^{2}\) m\({}^{-2}\) when the humidity index was in the range of 0.71 to 0.78. The values of GPP continued to rise as the humidity index rose from 0.35 to 0.53 (Figure 9c). The GPP remained stable when the humidity index was between 0.53 and 0.58. The GPP increased considerably once more as the humidity index rose from 0.58 to 0.9, and it peaked at 832.36 gC m\({}^{-2}\) yr\({}^{-1}\) when the humidity index was between 0.67 and 0.9. The dry areas  
Figure 8: Interaction between pairs of influence factors for LAI (**a**) and GPP (**b**). “#” indicates non-linear enhancement, and “**” indicates bivariate enhancement.  
Figure 7: The q values of factors with significant (\(p<0.01\)) impacts on the spatial heterogeneity of LAI (**a**) and GPP (**b**).  
with annual precipitation below 407 mm and a humidity index under 0.41 had the lowest values of LAI and GPP (Figure 9a-c). LAI steadily dropped from 1.3 to 0.72 m\({}^{2}\) m\({}^{-2}\) when ETo rose from 842.5 to 1099.97 mm (Figure 9d). The GPP values also decreased as ETo increased from 840.87 to 1060.17 mm (Figure 9e). The values of LAI and GPP were stable and higher when the solar radiation was between 145.97 and 167.45 W m\({}^{-2}\) (Figure 9f). When the solar radiation value exceeded 167.45 W m\({}^{-2}\), the values of LAI and GPP steadily dropped as the solar radiation level rose.  
The values of LAI and GPP increased continuously as the slope increased from 0.81\({}^{\circ}\) to 36.78\({}^{\circ}\) (Figure 9g). Forests had higher LAI and GPP values than other land use types, while barren had the lowest LAI and GPP values (Figure 9h). Regardless of LAI or GPP, the values of croplands and grasslands were very similar. Mountains had greater LAI and GPP values than other landform types (Figure 9i). Among all landform categories, the large  
Figure 9: Changes in the LAI and GPP values under different factor grades. Precipitation (**a**), humidity index for LAI (**b**), humidity index for GPP (**c**), ETo for LAI (**d**), ETo for GPP (**e**), solar radiation (**f**), slope (**g**), land use type (**h**), landform type (**i**). For landform type, “SUM”, “MUM”, and “LUM” indicate small, medium, and large undulating mountains, respectively.  
undulating mountains had the highest LAI and GPP values, while the platform's LAI and GPP values were lower.