Summary

The paper deals with the problem of determining those neighbours of a given tree that could be classified as active competitors. Active competitors were selected using as iterative procedure with specified competition zone radii and competition-elimination angles. A HEGYI-Index was calculated for each subject tree. Partial correlation coefficients were calculated, depicting the strength of the relationship between the HEGYI-Index and the current diameter increment. The results of the analysis indicate that in the given pine forests in the Kangwon Province, Korea, the competition-elimination angle should not exceed 30°, if the aim is to estimate diameter growth, based on the HEGYI-Index.