Study On Spatial Structure Optimizing Adjustment And Control Model Of Phyllostachys Edulis Stand

This study makes a less disturbed Phyllostachys edulis stand in Tianmu Mountain NationalNature Reserve of Zhejiang province as a research object, a spatial structure optimizingadjustment and control model of Phyllostachys edulis stand and its soluation method were studiedbased on the analysis of static and dynamic change character. The results show that:(1) Theuniform angle indexes decreased with increasing diameter classes, and the neighborhoodcomparisons decreased with increasing diameter classes, while the age mingling increased withincreasing diameter classes.(2) The spatial pattern of the stand presents a random distribution in2009and2012, but the2010and2011years showed an aggregation distribution pattern. Theaverage neighborhood comparison values of each year were close to0.5, suggesting that the standhas kept an intermediate status. The stand showed high age diversity and age isolation levels, andthe age mingling value increased as the years increased.(3) A spatial structure optimizingadjustment and control model of Phyllostachys edulis stand was established, its objective is spatialstructure, non-spatial structure is the main constraint. The model belongs to nonlinearmulti-objective optimization. The Genetic algorithm and Monte Carlo algorithm were used tosolve the model respectively and compared the difference of the two kinds of algorithm.(4) Thecomputational efficiency and operational results of Genetic algorithm were superior to the MonteCarlo algorithm. Under the same running time47.6096hours, the number of feasible solutionsof Genetic algorithm is obvious higher than Monte Carlo algorithm. The objective function valueof feasible solution of Genetic algorithm increased over time and finally shows an steady state,and showed a certain direction, but the objective function value of feasible of Monte Carloalgorithm randomly fluctuated over time.(5) The objective function value of optimal solution ofGenetic algorithm is0.2937and obviously higher than the value0.2172of Monte Carlo algorithm.Therefore, the optimal solution of Genetic was selected as the optimal cutting plan. Based on theplan, through spatial structure optimizing adjustment and control of Phyllostachys edulis stand, theobjective function value of stand spatial structure increases43.1287%more than that of beforecutting. The stand spatial structure was maximumly optimized, and the non-spatial structure wasalso improved. Therefore, this plan can be used for making cutting plan.