城市社区公园自生草本生态位及群落特征 ——以北京市西城区为例

城市化的快速推进导致生态环境遭受严重破坏，生物多样性急剧降低，城市公园对于保护和提升生物多样性具有关键意义。城市中的社区公园面积虽小，但数量最多，对于保护生物多样性具有巨大潜力。自生植物不仅是植物多样性的重要组成部分，而且能为动物提供必不可少的食源和栖息场所，其生态价值不容忽视。本文聚焦北京市西城区的社区公园，在比较分析自生草本的生态位宽度、重叠指数及植物多样性特征的基础上，探究自生草本的群落类型，以进一步明确高强度养护管理方式下小尺度城市绿地自生草本的群落特征。结果表明：（1）共记录到自生草本38种，隶属于22科36属。（2）荠菜、藜、龙葵、蒲公英等植物生态位宽度较宽；自生草本优势物种之间的生态位重叠指数（O_ik）介于0 ~ 0.62之间。（3）在植物多样性特征方面，月坛公园的Patrick指数和Shannon-Wiener指数最高，南礼士路公园的Pielou指数最高。（4）运用TWINSPAN分类法，将自生草本群落分为9个群落类型，Ⅴ藜+荠菜群落占比最高。最后，基于生态及景观价值提出社区公园自生草本的养护管理建议，为营造近自然、可持续的植物景观提供参考。

Niche and community characteristics of spontaneous herbs in community parks: A case study of Xicheng District of Beijing City

The rapid advancement of urbanization has led to serious damage to the ecological environment and a sharp decline in biodiversity. Although the areas of community parks are small, they have the largest number and great potential for protecting biodiversity. Spontaneous plants are not only an important part of plant diversity in the park, but also provide essential food sources and habitats for animals, therefore, their ecological values cannot be ignored. This paper focused on the community parks in Xicheng District of Beijing, based on the comparative analysis of niche width, overlap index and plant diversity of spontaneous herbs, the community types of spontaneous herbs were explored to further clarify the community characteristics of spontaneous herbs in small-scale urban green space under the mode of intensive maintenance and management. The results were as follows. (1) A total of 38 species of spontaneous herbs were recorded, belonging to 22 families and 36 genera. (2) Capsella bursa-pastoris, Chenopodium album, Solanum nigrum, Taraxacum mongolicum etc. had wide niche width; the niche overlap index (O_ik) between the dominant species of spontaneous herbs ranged from 0 to 0.62. (3) In terms of plant diversity characteristics, the Patrick index and Shannon Wiener index of Yuetan Park were the highest, and the Pielou index of the Park in Nanlishi Road was the highest. (4) Using TWINSPAN classification method, the spontaneous herb communities were divided into 9 community types. V Chenopodium album + Capsella