Spatial structure analysis of artificial forest of Pinus tabulaeformis,Robinia pseudoacaia and Platycladus orientalis from Lushan National Forest Park

We analyzed the spatial structure of Pinus tabulaeformis,Robinia pseudoacaia and Platycladus orientalis from Lushan national forest park with traditional stand structure indexes and two spatial structure indexes of uniform angle index and neighborhood comparison.Results show that the average angle indexes of Pinus tabulaeformis,Robinia pseudoacaia and Platycladus orientalis are 0.484,0.503 and 0.504.These data fit random distribution.Their average neighborhood comparison of DBH are 0.484,0.498 and 0.478,but the proportion of the strains whose neighborhood comparison of DBH is from 0 to 1 has not obvious distinction.This shows that the distribution of trees with different diameter levels is more even.However,differentiation degree of individual tree is more obvious.