扬州地区乡村绿化植物群落的结构特征

以植物群落学方法对扬州地区45个村庄的绿化植物群落的植被类型、物种组成、物种来源、物种多样性、使用频度、垂直与水平结构及植株健康状况等进行了研究，以期为扬州及周边地区的乡村绿化提供理论指导。采用样方调查法，共设置了标准样地121个，其中公共绿地（公园绿地、村口绿地等）的标准样地为20 m×10 m，道路绿地为100 m×2 m，河道绿地为20 m×10 m。结果表明:①扬州地区乡村绿化植物群落主要植被类型为常绿阔叶林和常绿落叶阔叶混交林，植物种类达227种，隶属于88科169属，乔、灌、草的应用比例依次为25.6%，32.2%，42.2%。②绿化植物使用频度在20%以上的乔木5种，灌木7种，草本0种。69.0%的乔木种与67.1%灌木种的使用频度都在5%以下，仅4.2%的草本种使用频度在10%以上。③绿化植物群落中Patrick丰富度指数、Shannon-Wiener指数、Simpson指数变化趋势基本一致，从大到小依次为灌木层、乔木层、草本层，乔木层、灌木层、草本层的平均物种数量依次为5.3，6.5，3.5种，Pielou指数从大到小依次为乔木层、灌木层、草本层。④大部分绿化植物属于小径级，中等高度，植物健康状况的平均得分为2.31，总体健康状况处于一般偏下，且绿化植物群落健康程度从高到低依次为城镇型村庄、乡村型村庄、城郊型村庄。

Structural characteristics of rural greening plant communities in Yangzhou

To provide theoretical guidance for greening construction in the rural area of Yangzhou and other surrounding regions, vegetation types, species composition, source of species, species diversity, frequency, vertical and horizontal structure, and plant health status in greening plant communities of 45 villages in Yangzhou were studied systematically using methods of phytocoenology. Analysis included the Patrick richness, Shannon-Wiener, Simpson, and Pielou indexes. Using the sample survey method, a total of 121 standard plots were set up, the size of standard plot for public green space (park green space, village green space, etc.) was 20 m×10 m, the road green space was 100 m×2 m, and the river green space was 20 m×10 m. Results showed that (1) the evergreen broadleaf forest was the most common vegetation type in rural greening plant communities followed by the evergreen and deciduous broadleaf mixed forest. Totally, 227 plant species from all sample plots were recorded belonging to 169 genera and 88 families comprised of trees (25.6%), shrubs (32.2%), and herbs (42.2%). (2) The frequency of plant species used for trees, shrubs, and herbs that was above 20% was 5 for trees, 7 for shrubs, and 0 for herbs. At the same time, the frequency of plant species used that was below 5% was 69.0% for trees and 67.1% for shrubs. However, for herbs the frequency of plant use above 10% was only 4.2%. (3) The Patrick richness index, Shannon-Wiener index, and Simpson index for greening plant communities were characterized by shrub layer > tree layer > herb layer; whereas the Pielou index was arranged in the order of tree layer > shrub layer > herb layer with average species of 5.3 (tree layer), 6.5 (shrub layer), and 3.5 (herb layer). (4) The majority of greening plants were small in breadth and of medium height, and the score for plant health status was 2.31 meaning the overall health status was generally low. In addition, the degree of plant health status for rural greening followed the general law of urban-type villages > remote suburban villages > suburban villages.