济南市主要公园乔木树种结构及动态

采用抽样调查的方法,对济南市的6个主要公园黄河森林公园、千佛山公园、环城公园、大明湖公园、五龙潭公园、趵突泉公园的树木进行调查。通过树种数、树种丰富度、树种多样性、树种均匀度4个指标对济南市各公园的树种组成结构进行分析,同时通过上述6个公园的树木总数、树木种类和胸径分布关系对公园树木结构特征进行分析。结果表明,大明湖公园的树种数最多,趵突泉公园的树种丰富度最大,千佛山公园的树种丰富程度最高,黄河森林公园树种最均匀。国槐（Sophora japonica）出现比例最高,占全部树木的10.69%。前20位树种总数占全部树木的75.06%,树木的数量构成具有明显的聚集性,出现少数树种主导整个群落的现象。从树木株数随胸径的分布看,同天然林存在差异,表现为近似的抛物线状。从不同胸径等级树种数分布上看,小径级的树种数多,大径级的树种数少,反映出济南市城市公园树种丰富度不断增加的趋势。

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.