Research On Selective Cutting Model Of The Chinese Pine Plantation Of Badaling Forest Farm In Beijing Based On Spatial Structure

Taking the Chinese pine plantation of Badaling forest farm as the research object,the paper selects non-spatial structure parameters and spatial structure parameters to calculate the diameter class distribution in forest stands,competition index based on intersection angle and spatial structure diversity index and analyze the features of the spatial structure of the Chinese pine plantation.According to operation requirements,set constraint conditions,build a cutting model based on the spatial structure of the Chinese pine plantation and simulate the model to provide references for developing operation of Chinese pine plantations.Set 5 piece of plots,namely,Plot 1 with 1260 ha,Plot 2 with 1660 ha,Plot 3 with 1460 ha,Plot 4 with 900 ha and Plot 5 with 1660 ha.Conduct diameter class integralization based on 2cm diameter class interval and analysis on diameter structures targeting the forest trees in the 5 plots with different densities and make drawings to show their respective relationship between the stem number of each diameter class and the diameter class of each plot.The drawings demonstrate that the diameter class distributions of these 5 plots basically obey their normal distributions.The maximum stem-number per diameter class of Land 2,3 and 5 is at 14cm diameter class and that of Land 1 and 4 is at 16cm diameter class.In general,there is no obvious difference among the 5 plots and the diameter class distribution is between 6cm and 26 cm with stem numbers mostly distributed between 12cm and 16cmThrough calculating spatial structure parameters,get the result that Plot 1 and 3 are in the status of random distribution,Plot 4 and 5 is basically in the status of clumped distribution and Plot 2 is in the status of uniform distribution.According to the bivariate distribution of angular scale and neighborhood comparison,can clearly see the distribution situation of forest stands.The average openness of forest stands is 0.33.The growth space of tress is common.According to the openness,can effectively get the lighting condition of forest stands.The DBH differentiation is small.To build the comprehensive indexes of forest stand spatial structure.The cutting model based on the comprehensive indexes of forest stand spatial structure can play a role in the operation adjustment of Chinese pine plantation and optimize the forest stand spatial structure.The forest stand structure adjustment through the cutting model improves the lighting condition of forest stands and increases the diversity of forest stand spaces,which provides better growth environment for forest stands and will give instructions to the operation of Chinese pine plantation in the future.The bivariate distribution of spatial structure parameters can better demonstrate the features of forest distribution in forest stands,more clearly find out the trees that need to be optimized,adjust forest stand structure unit in a more targeted way and more conveniently and easily define the scope that needs to be cut in real usage circumstances,which facilitate the harvest of felled trees through using the model and has better operability.