Study On Stand Structure Dynamic And Biomass For Mongolian Scots Pine In Plantation

Based on the data of stem analysis, branch analysis from 139 sample trees in 26 sample plots for Mongolian scots pine plantations with different age, different stand density, and different site, the diameter and height structure were discussed and diameter distribution model was established to predict the future stand dynamic. The growth model of forest investment factors of Mongolian scots pine plantations in eastern area of Heilongjiang province, such as average height, stand basal area and stand volume, were studied and forest growth and yield model were established to evaluate the future forest investment factors. The vertical distribution model of leaf biomass is developed through the study of relationship between leaf biomass distribution rules and forest conditions. The prediction model of leaf area was established according to the relationship between leaf biomass and leaf area. This paper found the releatioship among various component biomass of different size of tree and tree age. It developed the biomass prediction models of stem, branch, leaf and total height of single Mongolian scots pine tree of using the variables of diameter, height and their combination adopting CAR model. The volume and crown variables were added in these models to develop the biomass prediction models that is compatible with tree volumes. Combined biomass prediction models with diameter distribution evaluation model, various components biomass of Mongolian scots pine plantations with different site quality, foret age and forest density were predicted and the production structure of Mongolian scots pine plantations with different ages were studied. It can describe the forest structure dyanamic and the process of biomass accumulation, grasp the diversification rules of biomass structure of Mongolian scots pine plantations in different phases. The results are followed:1,The Weibull distribution with three parameters can describe the diameter and height distribution of Mongolian scots pine plantations, and its parameters can be predicted by the forest factors such as age; density and site index. The models can be used to describe the future forest diameter distribution.2,Using stand density index to measure forest density, the prediction model group were estiblished using interval instead of age to predict forest investment factors. They can predict the forest investment factors at any time and they are of high precision and stability, which can be used in study area.3,The vertical distribution of accumulative leaf biomass followed modified Weibull distribution. The whorls with maxium relative leaf biomass is at the location where relative depthe in crown is 0.45. Under the same forest conditions, the maxium of relative leaf biomass is decreased with the increasement of tree ages, and its location is gradually reduced. 4,The leaf area of single tree(LA) is related with its leaf biomass(Wl). The relationship can be expressed as followed equation: LA=0.01817+12.1692Wl.5,The optimization biomass models of various components are all CAR models and the best variables are diameter at breast height(D) and total height(H).They can describe the diversification of branch, leaf and total weight and the combination of them(D2H)can describe the diversification of stem better. Adding volume and crown factors to the biomass models to develop the models that is compatible with tree volume can improve the models' prediction precision.6,The biomass of single tree increased with the increasing tree age.The proportion of stem biomass is also increased with the incresement of tree age, but branch and leaf biomass is opposed with stem biomass.7,Combined biomass prediction models with diameter distribution evaluation model, various components biomass of Mongolian scots pine plantations with different site quality and foret age can be predicted. The relative average errors of vaiours components were less than 10%. Except leaf biomass model, the precision of all the models is above 95%.8,The Mongolian scots pine plantations density decreased with the increading forest age. The various components and total biomass of arbor layer in the stand are all increased with the increasement of forest site condition and age. The relative allocation proportion of stem biomass is increased with the increasing of stand age and the relative allocation proportion of branch and leaf were on the opposition.The study in this paper can provide theory base and management method for the development and application of Mongolian scots pine plantations so as to get more ecology and economy benefit and improve the management level of Mongolian scots pine plantations in our country.