Growth pattern to Density and Site Condition of Pinus tabuliformis Plantation in the Beijing Mountainous Area

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, which can provide a scientific basis for guiding the management of P. tabuliformis plantations. 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 three 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.