Compare of Spatial Structure of Two Mixed Stands in Suzhou Taihu Lake Watershed

In order to understand the features and situation of complex spatial structure along Taihu Lake that provides the basis for scientific management for forests. Two representative mixed forests in Taihu Basin Suzhou, Jiangsu Province were analyzed with traditional stand structure indices and four spatial structure indices of mingling, angle index, neighborhood comparison and opening degree. The results showed that the species richness of Ilex purpurea and Pinus elliottii mixed forest was relatively higher. Comparison of the parameters from the spatial structure, I. purpurea and P. elliottii mixed forest was better than Quercus and P. elliottii mixed forest. In I. purpurea and P. elliottii mixed forest, I. purpurea, Symplocos spectabilis may become dominant tree species. In Quercus and P. elliottii mixed forest, because of Q. acutissima and Q. variabilis growing space were constrained, their succession dominance could be decline， Q. glandulifera and Broussonetia kazinoki would become the new dominant species.