黑荆树造林密度试验*

对黑荆树１－５年生人工林分在２．０×２．０ｍ（Ａ），２．０ｍ×１．５ｍ（Ｂ），２．０×１．０ｍ（Ｃ），１．５ｍ×２．０ｍ（Ｄ）和１．０ｍ×１．０ｍ（Ｅ）５种密度下的生长．发育规律及其经济效益的研究结果表明：树高、胸径生长及其经济效益，随密度增大递减；单位面积树皮和木材产量随密度增大递增，但增幅随林龄增大减小；林分的数量成熟期随密度增大缩短，间代期也随之提早，Ａ、Ｂ密度为皮材兼用林最佳的造林密度；Ｃ

Experiment on Stand Density of Acacia mearnsii Plantation

This paper deals with the stand growth,development and economic return of black wattle(Acacia mearnsii) planted at spacings ranging from 1 m×1m to 2 m×2m at the age of 5 years old.The results showed that the height,diameter increment and economic return(judged by output/input) decreased as density increased;bark and wood yield per unit area increased with the increase of stand density while their increment ranges were smaller in old stands.The stands planted with denser spaeings matured earlier and their thining time was earlier too.Stands of lower densities(treatment A and B) are desirable for producing bark and timber.On the other hand,stands of higher densities(treatments C,D and E) are suitable for establishing fuelwood plantations.