Stand Growth Corresponding With Stand Structure In Plantation Of Pinus Tabulaeformis

The growth course of Pinus tabulaeformis artifical forest and the relationship between the growth course and the stand density to the diameter structure were measured, therefore, the relation model of the forest factor and the stand structure was established what the research object was Pinus tabulaeformis artifical forest with different age, different stand density, and different site in Daqing Mountain. The optimal stand density of Pinus tabulaeformis artifical forest in that area was discussed on the basis of the research result to provide the theory basis for managing Pinus tabulaeformis artifical forest in Daqing Mountain scientifically. The results are followed:1,The diameter and the height distribution of Pinus tabulaeformis artifical forest obey described normal distribution function. The stand density and the stand age are the dominant factor for influencing the stand diameter distribution. With the increasing of the stand density more, the skew of stand distribution decreases and the small size-class increases. With the increasing of the stand age bigger, the skew and kurtosis of the diameter distribution decreases.2,The order of biomass of different component of Pinus tabulaeformis artifical forest is arborous layer, litter layer and vegetable layer under forest from big to small. The relationship between the ground biomass and the biomass of trunk, branch and tree crown of individual can be expressed by the power function y=axb. The relationships among the trunk biomass of individual (y), the diameter at breast height (D) and height (H) is lny=4.496+0.737 ln(D2H). The relationships between the diameter at breast height and the branch biomass, and the canopy biomass, and the ground biomass of individual can be expressed by equations lny=-4.676+2.761ln(D) , lny=-3.084+2.205ln(D), lny=-1.831+2.1ln(D). The relationships between the stand density and the ground biomass of individual, and the ground biomass in unit area can be both simulated by the equation y=k/(1+aEXP(-bx))(x is the stand density, y is the ground biomass of individual or the ground biomass in unit area). The root age of Pinus tabulaeformis distributes in the range of 0-60cm soil layer mainly, and the root biomass in 0-40cm is the 60%-80% of the total root biomass. The relationship between root biomass of individual and the total biomass, and the ground biomass can be simulated by the equation y=aebx.3,The relationship between the stand density and the leaf area of individual can be simulated by the equation y=a+b(1-EXP(-kx)). With the increasing of the stand density, the leaf area index of Pinus tabulaeformis artificial forest increases, but the variance is small. The variance range of the leaf area index is 3.0-6.6m2/m2.4,The growth course of diameter at breast height, total height, timber volume and stand volume of Pinus tabulaeformis artifical forest can be expressed by Logistic growth equation y=k/(1+aEXP(-bx))(x is age,y is total increment.). According to the equation, the growth course of tree can be divided into three stages, initial growth stage, growth rapid stage and retarded growth stage. The growth rapid stage of the diameter at breast height of 30 years Pinus tabulaeformis is 10-21 years old, the total height is 7-18 years old, the timber volume and stand accumulation are 16-24 years old. With the increasing of the stand density, the age of the stand growth critical point becomes younger and the fast-growing duration period of DBH, individual volume becomes shorter, accordingly the stand will turn into slow-growing stage in advance. The influence of stand density on height growth is unregular. The relationships between the stand density and the diameter at breast height, and the individual timber volume, and the stand accumulation can be simulated by equation y=k/(1+aEXP(-bx)) (x is the stand density, y is the diameter at breast height, or individual timber volume, or the stand accumulation)5,Pinus tabulaeformis what grow in the shady slope in Daqing Mountain preceded than in the sunny slope. The optimum stand density when Pinus tabulaeformis is 30 years old is 3000-4000 stocks/ha in the shady slope and 2000-3000stocks/ha in the sunny slope.