Abstract:

Aims: This paper conducts a comprehensive review of literature from the past two decades, focusing on two primary objectives. First, it explores the composition of dominant weed species in urban lawns across China, including the types and characteristics of invasive weeds. Second, it investigates the key factors influencing the distribution and spread of weeds in urban lawns in China. This study aim to provide a theoretical foundation for the scientific management and control of weeds in urban lawns and help protect biodiversity and promote sustainable urban development. Additionally, these findings can support efforts at monitoring weed population dynamics to maintain ecological balance and enhance the health and sustainability of urban green spaces.

Methods: This study conducted a comprehensive review of the literature on urban lawn weeds in 98 cities across China between 2002 and 2024. A statistical analysis of the weed species identified in the literature was carried out after gathering information on dominant weed species, including their Chinese and Latin names, family and genus details, life forms, and flora. These data were used to determine the species, origin, degree, and route of invasion for invasive weeds. Furthermore, β-diversity was assessed using the Jaccard similarity index. The data for this study were sourced from the CNKI database, WANFANG DATA, and VIP database. Statistical analyses were performed using R and SPSS software. The correlation between invasive weed distribution and climatic factors was examined through a nonlinear relationship, and the primary climatic factors influencing the distribution of weed species in urban lawns were identified using redundancy analysis (RDA). Together, these methods enabled a deep exploration of the species composition, spatial distribution, and main influencing factors of urban weeds in China.

Results: (1) A total of 208 dominant weeds, spanning 40 families and 137 genera, were identified in urban lawns. The Compositae was the most prevalent in the literature, constituting 22.12% of the total. The geographical distribution of these flora is complex, with cosmopolitan families holding a significant advantage (23 families). However, at the genus level, the number of temperate distribution genera (57) surpassed that of tropical distribution genera (42), resulting in a tropical to temperate ratio of 2.33 and 0.74 at the family and genus levels, respectively. (2) A total of 37 species of invasive weeds were identified, belonging to 11 families, predominantly Compositae, Gramineae and Fabaceae (59.46%). This included 10 species of malicious invasive species, 11 species of serious invasive species, 4 species of local invasive species, and 12 species of general invasive species. The distribution of invasive weeds in southern China was notably concentrated. (3) The variation in weed composition among different cities aligns with the β-diversity theory, as variation was primarily influenced by geographical distance and climatic conditions.

Conclusion: Plants, particularly Compositae and Gramineae weeds, which are primarily annual and perennial herbs, hold a significant advantage over other species due to their widespread distribution. These plants demonstrate ecological adaptability and competitiveness in the ecological context of urban lawns. A considerable number of invasive weeds are present in these lawns, with some species exhibiting strong dispersal capabilities and posing serious threats to the existing ecological environment. These species are more concentrated in the southern region of the country, indicating that the area faces greater challenges in managing and preventing the spread of invasive weeds. The variation in weed composition between cities aligns with β-diversity theory which suggests species distribution is primarily influenced by geographical distance and climatic conditions. Future research should seek to more accurately assess the risk of invasive weed establishment and further investigate the mechanisms driving diffusion of dominant weeds. Considering the increased influence of global warming on ecosystem dynamics, it is essential to strengthen methods for predicting the distribution of dominant weeds, particularly non-native invasive species, and to conduct research on effective means of biological control. Additionally, a deep study of the life history of frequently occurring weeds is necessary to provide a scientific basis for effective prevention and control strategies.

Key words: weeds, urban lawns, dominant species, spatial distribution, Jaccard similarity index