不同年龄尾巨桉人工林林分结构特征研究OA

By analyzing the stand structure characteristics of 6-year—old,8-year—old and 10-year—old Eucalyptus urophylla X E.grandis plantations in Shangsi County,Fangchenggang City,Guan-gxi,the competition degree and spatial distribution characteristics of Eucalyptus Urophylla ×E.grandis plantations were understood,which provided a theoretical basis for the structural optimiza-tion of Eucalyptus Urophylla XE.grandis plantations.The results showed that:(1)The non-spa-tial structure characteristics of 6-year—old,8-year—old and 10-year—old Eucalyptus Urophylla XE.grandis forests were similar,and the tree height distribution structure and diameter distribution structure were generally normal distribution;(2)there was no significant difference in the angle scale of Eucalyptus Urophylla ×E.grandis stands of three ages,which was mainly between uniform distri-bution and random distribution,and there was a certain gap with the ideal model of horizontal distri-bution.The average size ratio of stands was 0.67,0.53 and 0.31,respectively.The stand with older age was more competitive than the stand with younger age;(3)the stand structure of E.urophylla× E.grandis plantation is more stable and more reasonable with the growth of trees,and the competition among trees is reduced.On the whole,the three age stands did not reach the ideal stand state,nor did they reach the cultivation goal of large-diameter timber of E.urophylla ×E.grandis.In the actual production,in different growth stages of trees should take appropriate ways to optimize and adjust its spatial structure,promote the stability of stand structure,ensure the forest wood properties,help to achieve the goal of Eucalyptus large diameter timber cultivation.