采用了机械取样和典型取样相结合的方法, 于2015—2016年对长三角地区筛选出的13个城市76处城市公园、道路和滨水绿地人工林449个样地进行了乔木树种调查, 分析了主要乔木的物种组成、分布、径级、盖度、生长情况等相关因子和成因, 旨在为森林城市建设与城市人居环境的改善提供科学依据. 结果表明: ①长三角地区城市人工林主要乔木树种共54科115属157种, 其中以蔷薇科种类最多(12属20种), 单种科占有比例较高, 种类组成相对分散; ②从区系组成看, 以温带地理成分为主(73属), 说明在乔木树种的运用中具有典型的温带性质; ③从重要值、盖度及相关因子来看, 乔木树种以香樟和二球悬铃木为主, 重要值之和达到27.45%, 且其中香樟占绝对优势, 不同类型的城市人工林主要乔木运用的差异较大; ④通过径级结构分析发现, 10 cm ≤ D（加权平均胸径）≤ 30 cm的树种构成了城市人工林主要高大型乔木, 包括无患子、黄山栾树、枫香等诸多乡土树种. 但从数量及分布来看极不平衡, 区域内香樟和二球悬铃木的覆盖度高达45.18%, 占有绝对地位, 相对物种多样性及群落稳定性较弱, 建议在以后的城市人工林建设中逐步增加其他树种的覆盖度.

Using a combination of mechanical and representative sampling, plots in 13 cities of the Yangtze River Delta Region were surveyed in 2015—2016; the survey consisted of 449 plots across 76 urban parks, roads, and waterfront greenbelt areas. As part of this study, we analyzed the factors and drivers for species composition, distribution, size, coverage, and growth vigor of the predominant trees located in the urban plots; the data provides a scientific basis for the future construction of forest cities and the improvement of urban human settlements. The results show that: ① In total, 157 tree species were recorded in the surveyed plots, which belonged to 115 genera and 54 families. The dominant families belonged to the Rosaceae group (20 species across 12 genera), with a high proportion of single families and relatively dispersed species composition. ② The plots were characterized by significant temperate features (73 genera), showing that the tree species have typical temperate properties in application. ③ The main tree species of the urban man-made forests were Cinnamomum camphora and Platanus × acerifolia, with coverage reaching 27.45%; specifically, Cinnamomum camphora was the dominant species. The utilization of trees across different types of urban plots varied considerably. ④ It was found that tree species with 10 cm ≤ D≤ 30 cm constituted the majority of tall trees in the urban plots, including many species of native trees such as Sapindus saponaria, Koelreuteria bipinnata 'Integrifoliola', and Liquidambar formosana. The quantity and distribution of the trees, however, was found to be extremely unbalanced. The coverage of Cinnamomum camphora and Platanus × acerifolia in the area was as high as 45.18%, and the relative species diversity and community stability were found to be weak. We recommend that the coverage of other tree species is gradually increased in the future construction of urban plots.