沈阳市城市森林结构与效益分析

Structure and ecological benefits of urban forest in Shenyang build-up area

采用样方调查方法对沈阳市 2 4 3km2 范围的树木进行每木实地调查 ,在地理信息系统应用软件ArcView 3.2平台上建立了基于CITYgreen模型的城市森林信息管理系统 .应用该信息系统分析了沈阳市土地利用及树木分布的格局、树种构成、树木密度、树高、胸径、健康状况等反映城市森林结构特征的指标 .结果表明 ,2 0 0 1年沈阳市有树 136种 ,1914 5 0 0株树木 ,森林覆盖率为 9.77% .2 5种主要树木占树木总数的 84 .78% .胸径小于 0 .2 5m(一类胸径 )和大于 0 .5m(三类胸径 )的树木占 82 .8% ;幼龄树 2 7%、中龄树 5 8%、老龄树 15 % ;84 %的树木健康状况为中等以上 .城市森林信息管理系统计算表明 ,沈阳市城市森林每年生态效益折合经济价值为 2 .6 5千万美元 .

Investigations were made in the sampling plots covering 243 km 2 of the Shenyang urban area,and the results were used as the input for the Urban Forest Management Information System (UFMIS),which was developed based on the model of CITYgreen. With this system,and using tree species,tree density,tree height grade distribution,tree DBH (diameter at breast height) grade distribution,and tree health condition as parameters,the land use and forest structure in Shenyang City were analyzed. It was found that there were 1 914 500 trees in Shenyang,belonging to 136 species. The 25 dominant species accounted for 84.78% of the total number of trees,and the forest coverage was 9.765%. Trees with DBH<0.25m and >0.5m accounted for 82.8% of the total,and the young,middle aged and old trees occupied 27%,58% and 15% of the total,respectively. The healthy status of 84% of the trees was above middle level. Therefore,the forest in Shenyang urban is at a stable stage. According to the statistical results from UFMIS,the ecological value of forest in Shenyang urban is as high as 26 526 955.1 USD in terms of economy.