A Review of Urban Pollinators Friendly Landscape

Objective In recent years, with the development of human society, many ecological problems have begun to emerge, and biodiversity is decreasing at an alarming rate. The Living Planet 2024 report, published by WWF, indicates that the average size of monitored wildlife populations has declined by 73% over the past 50 years (1970-2020). The stability of the Earth"s natural ecosystems is worsening and their resilience continues to decrease, which threats the normal functioning of the entire ecosystem. As we all known, Plants have always played a key role in the entire ecosystem, which provide us with a wide variety of resources as producers. For plants, pollinators play an important role. Their diversity maintains the stability of plant communities (the higher the diversity, the more benefits for stable reproduction), improves crop yields and quality. And it’s essential for urban aesthetics and cultural and biodiversity enhancement. However, due to accelerated urbanization, expansion of intensive agriculture and changes in habitat temperature and humidity brought about by climate change. Habitats suitable for pollinators to inhabit and live in are declining, and they are forced to migrate in search of more suitable habitat. Currently, thanks to the diversity of urban ecosystems and the heterogeneity of urban landscapes is improving, diverse green spaces such as large parks provide for the survival of pollinators, especially those rich in flowering plants. Therefore, urban green spaces have a significant potential to develop as pollinator habitats. In order to fully exert the role of urban green spaces in the protection of pollinator populations, we should incorporate urban green spaces into the pollinator protection system in the future and maximize their ecological benefits by increasing their habitat diversity as much as possible. For this reason, it is necessary to understand international pollinator conservation strategies, summarize methods for creating pollinator-friendly landscapes, and think about their future directions to better protect pollinator populations. Methods Based on VOS viewer software and Bibliometric website, this review visualizes and analyzes the relevant and valid papers screened from major literature websites, such as Web of Science Core Collection (SCI-Expanded), Google Scholar, and X-MOL Academic Platform, which hoped to summarize an overview of international research in the field of pollinator-friendly landscapes since the turn of the century and explore research priorities in the field of pollinator landscapes. Results The results of the literature analysis indicate that the field of pollinator-friendly landscapes was in a slow stage of development until 2007, with only a few studies conducted globally. From 2007-2012, scholars began to pay more attention to this field and the total amount of related literature began to increase. After 2013, pollinator-friendly landscape research has attracted the interest of scholars at home and abroad, and the number and growth rate of the literature have risen significantly, which peaked in 2021 with more than 200 publications. Although the amount of literature begins to decline after 2021, it is still at a high level. Four major research clusters in the field of pollinator landscapes were obtained by analyzing the keyword co-occurrence network of the literature: 1) Landscape fragmentation of pollinator habitats and their biodiversity conservation; 2) The role played by the ecological services of pollinators in agricultural landscapes and the development of conservation programs in agricultural landscapes; 3) Urbanization and Pollinator (Hymenoptera) Diversity Conservation; (4) Conservation of pollinator diversity by flowering plant resources and landscape planning. Research on the first three clusters focused on the period before 2020, after which scholars began to focus on the protection of pollinators by flowering plant resources, and further exploring specific measures for the protection of urban pollinator populations, which is about how to create pollinator-friendly landscapes. Conclusion On this basis, this review outlines the role of pollinators on urban ecosystems, and specifically summarizes how to create pollinator-friendly landscapes specifically in terms of migratory corridor building, plant selection, habitat creation, and ecological management, and finally reflects on the future development direction of pollinator-friendly landscape creation. Although there have been quite a number of related studies based on urban pollinator-friendly landscapes at home and abroad, there is still a continued depth in some aspects, especially the screening of pollinator-friendly plants, which has been weakly researched both at home and abroad. At present, although there are fewer studies on urban pollinator-friendly landscapes in our country, some studies on pollinator-friendly landscape creation have appeared, such as plant landscape design methods for butterfly habitats in Hangzhou and pollinator-friendly wildflower meadows creation methods. However, other aspects such as plant selection, ecological management and so on, still need to be researched. In view of the future development direction of urban pollinator-friendly landscapes, the following aspects can be considered: 1) Developing policies to improve urban pollinator protection systems; 2) Focusing on the role of non-flowering plants in pollinator protection; 3) Accelerating the propaganda of pollinator protection knowledge and speeding up the excavation and promotion of pollinator-friendly plants resources; 4) Improving the requirements for the use of various types of pesticides and accelerating the research and development of organic pesticides.