马尾松次生林幼龄种群结构和生长状况研究

A study on structure and growth of young population of secondary Masson pine forest

探讨了贵州省都匀地区马尾松次生林幼龄种群的年龄结构、分布格局及生长状况。结果表明,所调查的马尾松幼龄种群在4年之内,各年龄的个体死亡率很大,其幸存率分别是上一年的42.36％、72.18％和54.17％。种群总的水平分布格局多集群分布,但按年龄分解,则表现出分布格局的多样性。幼龄种群地径、树高结构的分布状况,大体呈左右下对称的单峰状偏态分布。对马尾松天然幼树地径生长有影响的,不是样地的平均密度,而是分布群团内的实际密度。由于密度过大,马尾松幼林生长不良,被压木多,林木分化严重。要经营好马尾松天然次生林,很有必要在幼年阶段就开始通过间苗、抚育等手段,进行幼龄种群的密度调控。

The age structures, distribution patterns and growth of young population of Masson pine in Duyun area of Guizhou province were preliminarily studied in this paper. The results showed that the mortality rate of individuals at different age gradations is high in the formation of young growth in 4 years. Distribution pattens of young population of Mas-son pine are wholly aggregated distribution, but vary at the age gradation levels. The structures of the ground diameter and height of young trees of Masson pine stands are broadly away normal distribution which is an unsymmetrical curve with single peak. Growth of the ground diameter is actually dependent on the number of individuals in clusters, not on the average density of stand. As result of over stand density, stand growth is bad,suppressed trees are many and individuals of stand are differentiated greatly. To better manage secondary Masson pine forest, it is very necessary to regulate and control stand density of young population by thinning and tending and so on at the initial stage of young growth.