Tree Species Structure and Its Dynamic in Parks of Jinan City
Trees were investigated by method of sampling survey in six parks in Jinan City, including Huanghe Forest Park, Thousand-Buddha Mountain ( Mt. Qianfo) , Around-the-City Park, Daming Lake, Wulong Lake Park and Bao- tu Spring. The tree species composition was analyzed by means of four indexes of number of tree species, species rich- ness, species diversity and species evenness, and meanwhile the tree structural characteristics were analyzed in terms of the tree number, the tree species and the distribution of different DBH classes. The results showed that the number of trees species was largest in Daming Lake Park, Baotu Spring Park had the highest tree richness, tree diversity index was highest in Mt. Qianfo Park and tree species evenness was the highest in Huanghe Forest Park. Sophora japonica was the first dominant species, accounting for 10. 69% of the total trees. The total of the first 20 dominant species surpassed 75.06% of the total individuals. The number of trees presented an apparent convergence, leading to the pattern that a few tree species dominated the entire community in parks. The distribution of individual trees regarding DBH classes was parabolic, which was different from the distribution of trees in natural forest. From the distribution of tree species with different DBH classes that there were more tree species with small DBH and fewer tree species with large DBH, it could be inferred that the tree species richness had an increasing trend in Jinan City.