镇江市低影响开发示范区植物群落特征与物种多样性

低影响开发示范区植物群落特征与物种多样性是植物群落发挥生态效益的关键，对低影响植物景观的营建与优化提升具有重要意义。以镇江市低影响开发示范区植物群落为研究对象，采用典型样方法、群落数量分析法等对样地群落植物区系、群落数量特征、群落结构因子、群落多样性进行分析。随机设置48个样地，以100 m2标准样地为主，共设样方204个。结果表明:①维管束植物共有181种，隶属于74科147属。乔木层以枫杨Pterocarya stenoptera，樟树Cinnamomum camphora，全缘叶栾树Koelreuteria integrifoliola等为优势种；灌木层以红叶石楠Photinia×fraseri，金森女贞Ligustrum japonicum ‘Howardii’，金丝桃Hypericum monogynum等为优势种；草本层以狗牙根Cynodon dactylon，鸢尾Iris tectorum，麦冬Ophiopogon japonicus等为优势种。②植物群落信息主要集中在乔木性状、灌乔性状比值、灌木多样性、草本性状以及乔木多样性等5个因子的描述上。③对乔木层而言，边缘绿地的多样性指数最高；灌木层各项多样性指数表现为道路绿地>边缘绿地>节点绿地>滨水绿地。④以灌木层物种重要值为数据源进行Q型聚类，根据样地群落外貌和聚类图，可将48个样地群落划分为13个类型。综合而言，各绿地类型物种多样性均表现出灌木>乔木>草本的一致趋势，物种丰富度总体偏低，群落内部结构相对单一。

Community structure and species diversity of a low impact development demonstration area in Zhenjiang City

To build and optimize the plant landscape with low impact development, plant community characteristics and species diversity in a low-impact development demonstration area, being key to ecological benefits of plant communities, were determined. Taking the plant community in the low-impact development demonstration area of Zhenjiang City as the research object, plant, community quantity characteristics, community structural factors, community diversity, and community clustering were analyzed through typical sample and quantitative analysis methods including a cluster analysis and principal factor analysis. 48 sample plots were set randomly with the 100 m2 standard plot as the main plot, and 204 squares were set in total. Results showed(1) There were 74 families, 147 genera, and 181 species of vascular plants. Pterocarya stenoptera, Cinnamomum camphora, and Koelreuteria integrifoliola were the dominant tree species; Photinia×fraseri, Ligustrum japonicum, and Hypericum monogynum were the dominant shrub species; and Cynodon dactylon, Iris tectorum, and Ophiopogon japonicus were the dominant herb species. (2) The plant community was described by five factors: tree characteristics, ratio of tree to shrub traits, shrub diversity, herb characteristics, and tree diversity. (3) For the tree layer, the diversity index of marginal green space was highest. Various diversity indexes of the shrub layer were shown as road green space > marginal green area > node green area > waterfront green area. (4) The importance values of shrub species were also used as data sources for the cluster analysis, which, according to appearance and clustering of the sample community, showed 48 sample land communities that could be divided into 13 types. In conclusion, all green space types showed a consistent species diversity trend: shrub > tree > herb. The species richness was low, and the internal structure of the community was single.