Quantitative analysis of stand spatial structure of Cunninghamia lanceolata non-commercial forest based on Voronoi diagram.
To analyze the spatial structure of Cunninghamia lanceolata non-commercial forest, the plantation
predominanted by the 24-year-old C. lanceolata located in Fushou Forest Farm of Yueyang City, Hunan
Province of central China was taken as the study object, and four structural parameters, i. e. mingling
degree, neighborhood comparison, aggregation index and storey index, were calculated based on the
Voronoi diagram that can determine the reference tree爷s neighborhood groups of trees. The results showed
that: 1) there were nine kinds of different sizes of spatial structure unit in this community, and the most
common phenomenon was that the reference tree had five close neighboring trees; 2) the average
mingling degree of stand was 0.23, indicating the simple spatial allocation and poor mixing of different
tree species; 3) the distribution of neighborhood comparison based on DBH changed with a fluctuant
pattern, and the stability of species in the arborous layer was good;4) the average aggregation index of
stand was 1.01. The individuals of tree presented the succession trend from aggregated distribution to
random distribution; 5) the average storey index of stand was 0.23, and the spatial configuration was
relatively simple in the vertical space.