A Study of the Spatial Structure of Cryptomeria fortunei Plantation in Chongzhou Forest Farm

In this paper,an analysis is made of forest spatial structure and diversity in the Chongzhou Forest Farm where the majority of the forests consist of pure stands.A detailed analysis of forest spatial structure was made,based on six one-quarter-hectare plots where all the trees and their coordinates had been assessed.The objective of the study was to provide a quantitative description of the spatial structure of the plots,using new parameters of spatial diversity i.e.neighborhood pattern,neighborhood comparison and mingling,and to present a method for comparative analysis of the six forest sites.The tree-based neighborhood pattern W_i can be used to characterize the spatial distribution of tree positions.It describes the degree of regularity of the spatial distribution of the four trees nearest to a reference tree i based on the classification of the angles α_j between the neighboring trees.The dominance which measures the proportion of n nearest neighbors of a given reference tree which are smaller than the reference tree,provides information about the relative status of a species within the population.Species diversity is evaluated by the tree attribute mingling which measures the proportion of the n nearest neighbors that do not belong to the same species as the reference tree.The variables described the distributions of spatial mingling,size differentiation and contagion,which could be easily interpreted allowing quantitative comparisons between complex forest structures.This approach undoubtedly offered great potential for conservation and sustainable woodland management.