The Study Of Stand Spatial Structure For Mongolian Pine Plantation

Based on the data of inventory in 15 sample plots for Mongolian pine plantation withdifferent age, different stand density. The correlation between crown overlapping coefficientand condition of stand were analyzed. The qualitative analysis of different competitive indexeswas analyzed according to principal component analysis method, The correlation betweenstem number cumulative distribution and relative diameter were developed according toRichards equation. Based on the minimum composition structure cell, the neighborhoodcomparison of diameter at breath height, total height and crown width and neighborhoodpattern were used as the indicators spatial relationship to describe the structure of single tree.The stand spatial structure parameter was used to select the intermediate cutting trees in the502 sample plot. The results indicated that:(1)Crown overlapping coefficient was positively correlated with stand density, negativelywith stand mean age and was not remarkably with condition of site Mongolian pine plantation.(2)Growth space competitive index, branch stretching and growth space indexes wereimportant index in the process of forest competition. (3)Stand diameter distribution ofMongolian pine plantation obeyed normal distribution. Stand mean diameter kept steadily instem number cumulative distribution curve in different stand structure stages. (4)Thedistribution of distances consistent was single -kurtosis distribution in minimum compositionstructure cell. (5)It had highly consistency in growth predominance aspect of target tree andadjacent tree in Mongolian pine plantation. (6)The distribution pattern of Mongolian pineplantation was even, random and aggregated. But 80 percent was evenly distributed. (7)Thestructure parameters after foster intermediate cutting had changed as follow: the uniform angleindex changed from 0.56 to 0.5; the structure changed from aggregate distribution to randomdistribution; the size ratio changed from 0.58 to 0.51 and the dominance of target trees instructure unit had enhanced.The study discussed new theory and method for plantation stand spatial structureoptimization, it has some theoretic and practical significance for adjusting the horizontaldistribution pattern of plantation stand and improving forest competition relations.