Analysis on Spatial Structure of Keteleeria evelyniana Mixed Forest in Central Area of Yunnan Province

The stand spatial structure of Keteleeria evelyniana mixed forests in central part of Yunnan Province was studied by means of three parameters including the aggregation index, tree species diversity mingling degree and the tree neighborhood comparison ratio. The results showed that the stand spatial distribution pattern for more than three nearest neighbor trees was uniform. The average species diversity mingling degree of the stands was 02322, indicating the low mixing degree. The mingling degree of deciduous tree species was higher than the coniferous tree species, while zero mixing was obvious to the Keteleeria evelyniana tree species. The average tree neighborhood comparison ratio was 0.52, indicating less variation and the stands were comparatively steady, and there was medium level competition among the trees. The distribution of the neighborhood comparison ratio of Keteleeria evelyniana was even, while there was strong differentiation among the associated tree species, The study showed that Pinus armandii and Alnus cremastogyne were the predominant tree species in the stands.