Biotic homogenization and rewilding of urban greening

Cities have become the main abodes for humans, and landscape plant species with their notable influence on the quality of life, are important components of the urban ecosystem. Human preferences for the plant species of urban greening have greatly facilitated the spread of non-native species, resulting in the homogenization of landscape plant communities across spatial scales. More concretely, homogenization makes a limited cohort of familiar species with widespread popularity, while these plants usually exhibit traits such as easy propagation, ornamental characteristics, and have a tropical origin. This has contributed to accommodating many climatically mismatched plants in cities. Therefore, the need to explore the climatic suitability and sustainability of landscape plants is especially relevant due to globalization and climate change. Landscape plant selections should not only pay attention to the existing landscape needs but also consider the sustainability of landscape plant species to climate change, especially for long lifespan woody plants. In the face of these serious problems in urban greening, the research found that the development of near-to-nature forests is an effective way to solve these problems, and the excellence of near-to-nature forests has been proven in Shanghai. The application of spontaneous urban plants (SUPs) is another effective way, and the biodiversity-friendliness of SUPs has also been proven in 59 major cities in China. To sum up, nature-based solutions with rewilding and providing room for natural processes are important to improve urban biodiversity and develop green spaces that are more natural and provide people with more genuine nature experiences.