## 4 Analysis of Results
### Climate Effects on Interannual Vegetation NDVI
The indirect effect of precipitation on vegetation is \(-0.119\); thus, the increase in precipitation inhibited the growth of vegetation by reducing the temperature in spring. The indirect effect of temperature on vegetation is \(-0.419\), indicating that the increase in temperature inhibited the growth of vegetation by reducing precipitation. Moreover, the indirect negative effect caused by the increase in temperature is greater than the direct promotion effect of temperature increase. The comprehensive effect of precipitation on vegetation NDVI is \(0.526\), meaning positive promotion. The comprehensive effect of temperature on vegetation NDVI is \(-0.235\), which indicates that warming was unfavorable to vegetation growth in spring. It is concluded that the effect of precipitation on vegetation growth in Ordos City was greater than temperature, and precipitation was the key factor affecting vegetation growth in spring. In summer, the direct effect of precipitation on vegetation NDVI is \(0.534\) (shown in Figure 6), which indicates that the increase in precipitation promoted vegetation growth. The direct effect of temperature on vegetation NDVI is \(-0.020\), which was basically negligible. The indirect effect of precipitation on vegetation is \(0.018\); thus, precipitation promotes the growth of vegetation by reducing the high temperature. The indirect effect of temperature is \(-0.471\), which indicates that temperature inhibits the growth of vegetation by reducing precipitation in summer. The comprehensive effect of precipitation on vegetation NDVI is \(0.552\), which means positive promotion. The comprehensive effect of temperature on vegetation NDVI is \(-0.471\), which indicates that the increase in temperature inhibited vegetation growth. It is concluded that the effect of precipitation on vegetation growth in Ordos City was greater than temperature, and precipitation was the key factor affecting vegetation growth in summer. In autumn, the direct effect of precipitation on vegetation NDVI is \(0.506\) (shown in Figure 6), which indicates that the increase in precipitation promoted vegetation growth. The direct effect of temperature on vegetation NDVI is \(-0.188\), meaning an increase in temperature inhibited vegetation growth. The indirect effect of precipitation and temperature on vegetation NDVI are \(-0.017\) and \(0.046\), which are basically negligible. The comprehensive effect of precipitation on vegetation NDVI is \(0.489\), which showed a positive promotion effect. The comprehensive effect of temperature on vegetation NDVI is \(-0.142\), which indicates that the increase in temperature inhibited vegetation growth. It is concluded that the effect of precipitation on vegetation growth in Ordos City in autumn was greater than temperature, and precipitation was the key factor affecting vegetation growth. Generally, precipitation was the main climate factor in the vegetation growth compared with the temperature in Ordos City. The increase in precipitation promoted vegetation growth directly, while an increase in temperature showed a negative effect by reducing precipitation in the whole growing season. However, there were seasonal differences in the inhibition influence of temperature increase. In spring and summer, the indirect effect of temperature increase leads to the inhibition influence. The direct effect of temperature increase induced the inhibition influence in autumn. Figure 6: Path analysis of the effects of precipitation and temperature on vegetation NDVI.