Characterizing Composition Profile and Diversity Patterns of Spontaneous Urban Plants Across China's Major Cities

Spontaneous urban plants (SUPs) constitute an important component of urban vegetation, but they have received less attention in urban biodiversity and ecological research, especially at the regional scale. We comprehensively reviewed the occurrence records of SUPs in 59 major cities across China's geographical regions. We systematically analyzed floristic composition profiles and diversity patterns of SUPs at the regional scale and explored their causative factors. The study identified 1211 SUP species through an extensive search of floristic databases and records in tandem with fieldwork. The species composition of SUPs, displaying a spatial association with climatic zones, is primarily driven by climatic factors. The life-form characteristics of SUP species are related to geographic scale, with more diverse perennials at the regional scale. The high proportion of native species indicates that diverse urban habitats are amenable to local-species colonization as well as biodiversity enrichment and accumulation. However, in the context of globalization, continual species exchanges between neighboring regions at different scales may significantly exacerbate urban-biota homogenization. In conclusion, our study provided a regional-scale case of a synoptic SUP profile. The results furnished a scientific basis to understand the ecology and suitable habitats for SUPs in continually expanding and densifying cities. The findings could inform sustainable solutions for urban ecological planning and management of spontaneous nature in cities