华北落叶松人工林天然更新及与土壤因子的关系

Natural regeneration of the Larix principis-rupprechtii plantation and its relation to the soil factors

为了更好的理解华北落叶松人工林天然更新动态及其与土壤化学性质的关系,以塞罕坝地区不同林龄(Ⅲ:20~30 a,Ⅳ:30~40 a)华北落叶松人工林为研究对象,基于18块标准地(50 m×50 m)的调查数据,采用回归分析等方法对不同龄级林分的更新幼苗生长及与土壤化学性质之间的关系进行了分析。结果表明:(1)2个龄级林分更新幼苗高生长、基径生长与年龄均呈指数函数关系,高度与基径呈线性相关;(2)Ⅲ龄级林分幼苗高随基径增长速率小于Ⅳ龄级林分;(3)pH值和土壤全磷含量对Ⅲ龄级林分华北落叶松幼苗更新密度有显著影响,而在Ⅳ龄级林分pH值和土壤全钾含量对幼苗基径、苗高和苗龄均有显著影响。

In order to better understand the natural regeneration dynamics ofLarix principis-rupprechtii and its relation to the soil chemical factors, we conducted a field vegetation survey in 18 plots （50 m ~ 50 m） of two age classes （III age class, 20-30 years; IV age class, 30- 40 years） in a Larixprincipis-rupprechtii plantation. Regression analysis and correlation analysis were used to study the growth of natural recruited seedlings and the influences of soil chemical factors on regeneration establishment. The results showed that： （1） both seedling height and basal di- ameter had an exponential function correlation with age. There was a linear correlation between the seedling height and the basal diameter; （2） with the growth of basal diameter, the growth rate of seedling height was higher in the stands of III age class than that of IV age class; （3） soil pH and total P content had significant effects on the density of natural recruited seedlings in the stands of Ⅲ age class, while in the stands of IV age class, soil pH and soil total K content were the main factors affecting basal diameter, height and age of seedlings.