Abstract: Data from 4 100m×100m natural forest plots,then uniform angle index and pair-correlation function are used to analyze the spatial patterns of trees in forest plots with varying areas. The result shows that thecorresponding tree spatial distribution patterns are related to plot areas. Patterns become stabilized with increasing plot areas, indicating that foreststructures should be analyzed with data from plots which are big enough. According to our study, 2500m² is appropriate for minimum plot areas.

Key words: forest structure, minimum area, tree spatial distribution pattern, uniform angle index, pair-correlation function