摘要
为探讨初植密度对中国沙棘林的林木生长过程及主要生长特征的影响,在毛乌素沙地布设了初植密度为2 500株/hm2、4 444株/hm2、10 000株/hm2、40 000株/hm2的中国沙棘林田间观测试验。根据测定结果,分析了中国沙棘林的林木生长过程及主要生长特征(生长量上限、生长量增长率、速生期迟早、速生期长短)与其初植密度的关系。结果表明:(1)初植密度的变化没有改变林木树高、地径、冠幅的"慢-快-慢"生长节律,采用Logistic方程回归结果可分别解释其变异的99%、98%、93%。(2)初植密度的变化改变了林木生长过程的主要特征。其中,树高生长量上限及树高生长量增长率随其初植密度的增大呈现先上升后稳定的态势,地径生长量上限、地径生长量增长率、冠幅生长量上限随其初植密度的增大呈下降的态势,冠幅生长量增长率随其初植密度的增大呈现先升后降的态势。(3)初植密度变化对林木冠幅生长特征的影响最大,对地径生长特征影响次之,对树高生长特征影响最小。且在不同初植密度下均是林木的冠幅首先进入速生期,其次是树高,最后是地径。
Experimental study was conducted at Mu Us sandy land to explore the effect of planting density on growth process and growing characteristics of Hippophae rhamniodes subsp, sinensis, the tested planting density were 2 500 trees/hm2, 4 444 trees/bin2, 10 000 trees/hm2 and 40 000 trees/hm2 respectively. In accordance with the experimental results, the tree growth process and growing characteristics of Hippophae rhamniodes subsp, sinensis forests were analyzed. Three aspects of resuhs were achieved： （1） The difference of planting density did not change the growing rhythm of ＇ slow-fast-slow＇ , the variation of height, basal diameter and crown density could be explained by Logistic equation to 99 %, 98 % and 93 % respectively; （2） The planting density affected the main characteristics of growing process of the trees, among the growing indexes, the upper limit and increase rate of tree height showed the tendency of increase at the beginning and then stable with the increase of planting density ; the up- per limit and increase rate of basal diameter, and the upper limit of crown width, showed the tendency of decrease with the increase of planting density, however the growth increment of crown width showed the tendency of increase at the beginning and then decrease with the increase of planting density; （3） The effect of planting density im- posed the biggest effect on the growing characteristics of crown with, next came the effect on basal diameter, and the effect of height was the least. Moreover, under different planting densities, shared the common characteristics of the crown width was the first index achieve the fast-growing stage, next came the tree height, the basal diameter was the index achieve fast-growing at the last.
出处
《西部林业科学》
CAS
北大核心
2012年第6期78-83,共6页
Journal of West China Forestry Science
基金
国家自然科学基金项目(31070551)
国际科技合作项目(2008DFA32270)
关键词
中国沙棘林
初植密度
生长
过程
特征
Hippophae rhamniodes subsp, sinensis forest
planting density
growing
process
characteristics
