种植密度对桉树苗生物量分配的影响

Effect of Planting Density on Biomass Allocation of Eucalyptus robusta Seedlings

为探究种植密度对桉树苗生物量分配的影响,文章以广西柳州三门江某林场的桉树为研究对象,考察了两种种植密度下桉树苗生长性状、生物量积累以及分配情况。结果显示,高种植密度植株在试验期内的直径和树高均低于低种植密度,平均直径与平均树高均在3、4月龄时表现出显著差异,低种植密度植株的冠幅和冠长均显著高于高种植密度,种植密度过大不利于植株的生长发育。随着种植密度的减小,各器官和全株的生物量积累均随之表现出增大的趋势,各器官生物量比均为:枝生物量比<根生物量比<茎生物量比<叶生物量比。较小的种植密度条件下,尾巨桉更倾向于选择向地上器官分配生物量,而降低地下部分器官的生物量分配比例。

In order to explore the effect of planting density on biomass allocation of Eucalyptus robusta seedlings,this paper studied the growth characteristics,biomass accumulation and biomass allocation of Eucalyptus robusta seedlings under two planting densities in a forest farm in Sanmenjiang.The results showed that the diameter and tree height of plants with high planting density were lower than those of plants with low planting density during the experiment period,and the average diameter and tree height were significantly different at 3 and 4 months of age.The crown width and crown length of plants with low planting density were significantly higher than those with high planting density,and too large planting density was not conducive to the growth and development of plants.With the decrease of planting density,the biomass accumulation of all organs and whole plants showed an increasing trend,and the biomass ratio of all organs was as follows:branch biomass ratio<root biomass ratio<stem biomass ratio<leaf biomass ratio.Under the condition of low planting density,Eucalyptus robusta preferred to allocate biomass to aboveground organs,while decreased biomass allocation ratio to underground organs.