Zhang Nan, Dong Li, Hao Peiyao, Yan Hai, Wang Kuo, Luo Yang

(a. College of Landscape Architecture; b. National Engineering Research Center for Floriculture, Beijing Forestry University,Beijing 100083, China)

Abstract: Through strati? ed random sampling to the 142 transects, the structure of street trees in central districts of Beijing, differences in species composition, application frequency, diversity index, structure of DBH(Diameter at breast height)，composition of the tree height and aspection characters were investigated. The results show that the street trees in central districts can be classi? ed in 21 kinds of 13 families, the ratio between deciduous and evergreen trees was 24:1; the street trees possessed comparatively high species richness, but didn’t evenly distributed; the old districts had a lower diversity compared to the new districts; the distribution of DBH structure of the street trees in old district was relatively larger and the new district was smaller; the composition of the tree height between them had no signi? cant difference; Taking account of seasonal phenomena structure, the street trees in the central districts displayed mainly with summer aspection and fall aspection and the spring landscape appeared relatively weak. These results highlight the needs to introduce new varieties of street trees, and to select an appropriate and diverse mix of deciduous and evergreen tree species for new planting.