B. H and height per year are over 2.5 cm and 1.3 m at abotit10-year-old, with the age of tree increasing 10 year, the D,B,H per year will diminish 0.3 cm,but the heightper year is still 1.0m.

• 通过1047株毛白杨优树生长量的分析，得出了选优的绝对值标准如下：10年生左右时，年均胸径生长量2.；5cm以上，年均树高1