Preliminary study on the growth and adaptation of Pinus densiflora var．zhangwuensis

Zhangwu pine(Pinus densiflora var．zhangwuensis)is a natural hybrid of P．densiflora．Studies show that Zhangwu pine has full terminal buds，with high survival in grafting． The diameter and height of 1 and 2-year-old seed-lings are larger than those of P．sylvestris var．mongolica，P．densiflora and P．tablaeformis．The heights of 2-year-old seedlings are 36％，51％ and 33％，respectively，higher than that of the latter thre pines．The 11-year-old tres of Zhangwu pine is significantly larger than those of P ．sylvestris var． mongolica．with 82％ higher in height and 47％bigger in diameter．Zhangwu pine is also resistant to drought and disease，so it is a promising variety for afforestation in the Three-north Region，and worthy of propagation and extension．