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以福建滨海沙地486块木麻黄林标准地的调查数据为基础,探讨木麻黄树冠的变化规律和林分结构特征,进而提出预估树冠生长动态的数学模型。研究结果表明,林木冠幅和冠长先是随着木麻黄的生长发育而平稳增长,大约在过熟阶段的35年左右开始呈现下降态势;相对冠长在幼林时期前3年呈上升趋势,4年生后开始下降,但12年时出现小幅增长,而后随着时间的推移呈现稳步降低的态势;树冠系数总的变化趋势是随着时间的推移而不断减小,但在12～34年之间树冠系数下降的幅度较小,3年以后下降幅度增大。回归分析结果表明,木麻黄树冠(冠幅与冠长)与树高、胸径生长量呈线性正相关,由此建立了兼容性冠长与枝下高模型。
Based on the survey data of 486 Casuarina equisetifolia in coastal area of Fujian coast, the change rule and stand structure characteristics of Casuarina equisetifolia crown were discussed, and the mathematical model for predicting crown dynamic growth was put forward. The results showed that the crown width and crown length of wood first increased steadily with the growth and development of Casuarina equisetifolia, and began to decline about 35 years after overripening stage. The relative crown length increased in the first 3 years of young plantation period. 4 It began to decline after birth, but it increased slightly in 12 years and then decreased steadily with the passage of time. The total change trend of crown coefficient decreased with time, but in 12 to 34 years The decrease of crown coefficient is smaller, and the decline rate increases after 3 years. The results of regression analysis showed that crown crown and crown length had a positive linear correlation with tree height and DBH growth. Thus, a compatible model of crown length and branch height was established.