Analysis of Growth Process and Partition of Growth Phase on Poplar Clone I-69

According to the survey data of 290 valuation areas,the authors quantitatively analyzed the relationship between the crown characteristic and growth with canonical correlation analysis method;fitted Richards growth model of diameter at breast height,height of tree and volume in different planting density and different site index;distingusished growth phase with ordinal sample cluster method by variable annual growth increment of diameter at breast height and height of tree; analyzed characteristic of each growth phase in different planting density and site index.The results showed that poplar clone I-69 is with characteristic of very distinct fast growth.In the condition of high planting density,the effects of site upon growth and yield are been weaken.For the sake of cultivating plantation for the plywood,the site with SI 20 m or 22 m and planting density 156 or 204 trees·hm-2 should be adopted.