Adjustment approach to boundary effect on aggregation index and its application

Abstract

Calculating aggregation index by the sample-plot data used to lead to computing error due to the existence of a boundary effect. Here, we suggest a method for adjusting boundary effect in the analysis of spatial patterns at different stages of development of the broad-leaved Korean pine forest. This method is good for the reasonable management and biological control of the forests. The total station was used to sample the relative coordinates data at four corners of the temporary sample plot and of each tree in the field. Based on the sampling data, a correct approach to the boundary effect on aggregation index was put forward to the spatial pattern analysis of the broad-leaved Korean pine forest in its different stages of development. The results showed that the forest trees grew in a clumped pattern in the stage dominated by the pioneer trees, and that the trees were distributed in a random pattern in the stage dominated by the companion trees or in the mature stage. The spatial pattern of the broad-leaved Korean pine forest changing from clumped to random distribution is influenced by biological characteristic, the adaptive strategy of tree species and the natural disturbance in its entire development.