北京油松人工林生长对密度和立地的响应

Growth Pattern to Density and Site Condition of Pinus tabuliformis Plantation in Beijing

采用样地调查和树干解析方法,研究北京山区不同林分密度和立地条件下油松人工林生长规律,分析林木生长过程对密度、郁闭度和立地的响应关系。结果表明:胸径、树高、材积生长量与密度、郁闭度呈负相关,与立地指数呈正相关;高密度林分胸径、树高连年生长量与平均生长量相交时间比低密度林分提前约3 a,抚育起始期范围在15~21 a;根据材积连年生长量和平均生长量交点可知,研究区油松人工林在40~45 a达到数量成熟;在开展油松人工林经营过程中,确定抚育间伐起始期需同时考虑林分密度和所处立地条件,以更好促进保留木健康生长,同时应在林龄达到40 a前确定最终保留的目标树,以实现森林全周期可持续经营,为指导油松人工林经营提供参考依据。

In this study,we investigated the growth pattern of Pinus tabuliformis plantation under different stand densities and stand conditions in Beijing mountainous area,and used the plot survey and trunk analysis method to reveal the response of the plantation growth process to density,degree of canopy closure and stand conditions.The results of the study showed that diameter at breast height(DBH),tree height(H)and volume(V)growth were negatively correlated with density and degree of canopy closure,and positively correlated with stand index;the intersection time of DBH,H of annual growth curve and average growth curve in high-density stands was about 3 years earlier than that in low-density stands,and the beginning of the thinning ranged from 15 to 21 a;according to the intersection point of volume annual growth and average growth cruves,P.tabuliformis plantations reached quantitative maturity in 40–45 a.During the management of the P.tabuliformis plantations,the starting period of the thinning should take into account the stand density and the site conditions,so as to promote the growth of the retained trees,and the target trees should be determined before the age of the plantations reaches 40 a,in order to achieve the whole cycle plantation sustainable management goal and provide reference for guiding the management of P.tabulaeformis plantation.