Analysis of stand spatial structure of Platycladus orientalis recreational forest based on Voronoi diagram method.

To explore the approaches to regulate its stand structure, spatial structure (including aggregation index, mingling, neighborhood comparison, and open degree) of typical forest stand in Xishan National Forest Park of Beijing was analyzed by using Voronoi diagram method. Results indicated that: 1) the average aggregation index of stand was 1.31. The individuals of tree displayed an uniform distribution pattern. 2) The average mingling of stand was 0.427. The degree of segregation among tree species was low and the spatial configuration was relatively simple. 3) The average neighborhood comparison based on DBH and tree height was 0.512 and 0.497, respectively. The differentiation of DBH and height was not significant, which indicated a middle level of competition. 4) The average open degree of stand was 0.320. Thus, the stand was relatively open and had adequate growing spaces. In conclusion, spatial structure of this recreational forest was basically reasonable. For the purpose of improving recreational value, stand spatial structure can be optimized through little thinning or adding native broadleaved trees.