[Prediction of potential distribution area of the spruce forest on the central Tianshan Mountain based on site index.]

This paper predicted the potential distribution area of the spruce forest on the central Tianshan Mountain, through determining the site index thresholds, using 3S and spatial modeling technologies to build a site index model with water, heat, terrain and other factors, based on the current site conditions there. The results showed that the potential distribution area simulated by the site index model was not significantly different with the current actual distribution area, but had a significant difference with the non-spruce forest area. Based on the built site index model, there was a large potential distribution area, which occupied 6.4% of the total research area, i.e., 7.01×10 ³ hm ² of forest lower boundary zones, glades, shady and half shady slope areas, and could be used for the future forest development.