城市森林结构的量化研究——以沈阳树木园森林群落为例

采用遥感图像判读和野外调查相结合的方法，定量分析了沈阳树木园植物群落的物种结构及空间格局。结果表明，沈阳树木园植被的生长状况良好；物种丰富，其中黄蘖(Phellodendron amugense)、刺槐(Robinia pseudoacacia)、榆树(Ulmus pumila)在树木株数和相对优势度上均占优势，为群落的主林木；植被在高度和胸径上的分布均表现为具有向上发展的潜力，整个植被群落正处于一个快速的生长期，属于发挥生态效益的最佳时期,沈阳树木园的树种多度与基于叶面积的相对优势度之间无明显关联，数量上占优势的树种，其相对优势度不一定很高，沈阳树木园植被树木株数与不同树高等级间的分布关系表现为上凸的曲线，随着树木高度级的增加，树木株数开始分布比较平稳，当高度超过12m后，树木株数明显减少，曲线急骤下降，树木株数分布与不同胸径等级间的关系也呈现类似的情况。

Quantitative analysis of urban forest structure: A case study on Shenyang arboretum

The spatial features and attribute data of urban forests in Shenyang arboretum were acquired by using aerial photographs and field investigation. After systemic and quantitative analysis of the species composition and spatial distribution pattern of urban forest community based on geographic information system (GIS),the following results were achieved: 1) the vegetation in the arboretum was rich and in a good condition. Phellodendron amurense,Robinia pseudoacacia ,and Ulmus pumila were the main species according to their abundant individuals and relative dominance. The spatial distribution pattern of this vegetation indicated that it was in a growing level and in the best state for ecological benefits; 2) the tree species relative dominance based on vegetation quantity had no distinct relationship with the species abundance,and the species having abundant individuals might have a low relative dominance; and 3) the curve displayed in the relationship diagram between tree individuals and tree height showed ascending and protruding. With the increment of tree height class,the individuals were unchanged nearly at the beginning,but when the height was more than 12 m,the individuals reduced distinctly,and the curve displayed a quickly declined trend. The relationship between tree individuals and tree diameter at the breast height (DBH) showed the same result.