Crown Structure For Mongolian Pine Plantations

The data used in this study collected from stem analysis, branch analysis and biomass surveying data of 62 sample trees in 11 sample plots for Mongolian pine plantations with different age, different stand density, and different site. The branching structure of the primary branches, spatial distribution characteristics of the branches, crown shape, the relationship between crown structure with the size of sample tree, stand conditions, and management, and losing rings of branches for Mongolian pine plantation were studied by using the linear and nonlinear regression models.The results indicated that: 1) Total number and whorl number of branches within a living crown in Mongolian pine plantation were related with diameter at breast height (DBH), total tree height (HT), and crown length (CL). The branch numbers of every whorl did not relate with the tree size, stand density, stand age, and site quality. 2) The locational distribution along the stem was effect on stand density for the stand with same age. However, the locational distribution of tree was similar for the different age with the same density. 3) Branching pattern of the primary branches around the bole followed a uniform or rectangle distribution. 4) Approximate normal distribution was appropriate to reflect the foliage mass distribution of tree and it reaches the maximum when the relative depth into crown (RDINC) is about 0.6. The cumulative foliage mass was increased with depth into crown (DINC) and reached maximum at crown base. 5) Based on the theory growth equation, the crown profile models, including branch diameter, branch length, angle of origin, branch chord length, and crown radius of primary branches, were developed from branch attributes and tree variables by using the nonlinear regression model. The test result from the independent test data set showed that these models were suitable for predicting the crown profile in Mongolian pine plantation.6) Lost rings increased with DINC increasing and 87.6 percent of the branches was not losing rings in Mongolian pine plantation.Overall, the relationship between crown structure of canopied stand and environment condition (stand condition and management), the structure and distribution of the foliage and branch mass, and the crown profile models based on branch attributes, tree size and stand condition for Mongolian pine plantations studied in this paper could directly and obviously reflect the spatial structure of the stand, the competition among trees, and stand density. There results will provide the scientific foundation for developing the visual model for Mongolian pine plantation and forest intensive management.