作　　者： ;

机构地区： 华南农业大学林学院

出　　处： 《武汉植物学研究》 2002年第3期209-212,共4页

摘　　要： 用竞争密度效果的倒数式分析了 I- 6 9杨 (Populusdeltoids)的生长过程。随着时间的推移 ,C- D曲线在双对数图上向上移动。生物时间τ(τ被定义为逻辑斯蒂生长曲线中生长系数λ(t)的积分 )与物理时间 t的关系可以用双曲线方程表示。 C- D效果倒数式 (即 1/ w =Aρ+B,式中 w和ρ分别代表平均单株材积和密度 )中的系数 A和 B被求出。随着生物的时间τ的增加 ,系数 A急剧增加到最大值后逐渐下降 ,而系数 B呈指数下降 ,倾向于接近零。随着林分的生长 ,生长系数λ(t) The competition density (C D) effect for Populus deltoides stands was analyzed using the reciprocal equation of the C D effect, i.e. 1/w=Aρ+B, where w and ρ respectively represent mean stem volume and density. The C D curve, which is given by the reciprocal equation on logarithmic coordinates, shifted upward with the progress of time. The relationship between biological time τ and physical time t followed a hyperbolic curve. The coefficients A and B included in the reciprocal equation were calculated at each growth stage. With increasing τ, the coefficient A increased abruptly up to a maximum value, whereas the coefficient B decreased exponentially and tended to close to zero. The λ(t) decreased with increasing stand age.

关 键 词： 杨 竞争密度效果 生长特点

领　　域： [农业科学] [农业科学]