I-69杨竞争密度效果分析

详细信息

Growth Analysis on the Competition-Density Effect in Populus deltoids Stands

1.
College of Forestry, South China Agricultural University, Guangzhou 510642, China
2.
Laboratory of Ecology and Systematics, Faculty of Science, University of the Ryukyus, Okinawa 903-0213, Japan

摘要: 用竞争密度效果的倒数式分析了I-69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)倾向于下降.
- C-D效果 /
- 倒数式 /
- I-69杨
Abstract: 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 Aand Bincluded in the reciprocal equation were calculated at each growth stage. With increasing τ, the coefficient Aincreased abruptly up to a maximum value, whereas the coefficient Bdecreased exponentially and tended to close to zero. The λ(t) decreased with increasing stand age.
- C-D effect /
- Reciprocal equation /
- Populus deltoides