Exploring the effect of ecological land structure on PM2.5: A panel data study based on 277 prefecture-level cities in China

In the context of serious urban air pollution and limited land resources, it is important to understand the environmental value of ecological land. Previous studies focused mostly on the effectiveness of a particular type of green space or the total amount of ecological land on PM2.5 and have rarely analyzed the association between ecological land structure and PM2.5 systematically and quantitatively. Therefore, we took 277 cities in China as an example, comprehensively compared the results of different models, and selected a spatial Durbin model using time-fixed effects to dissect the degree of influence of ecological land and different land types within it on PM2.5. The urban ecological land use structure was closely related to PM2.5, and the higher the proportion of ecological land use was, the lower the PM2.5. The degree and direction of influence of different types of land functions within ecological land on PM2.5 differed, with forests, shrubs, and grasslands causing a weakening impact on PM2.5, while wetlands and waters did not have a weakening role. The degree of reduction of PM2.5 by a single type of ecological land was significantly smaller than that by a composite type of ecological land. Green space should be comprehensively considered, designed and adjusted in urban planning to continuously optimize the ecological spatial structure, increase landscape diversity and maximize ecological benefits. The findings of this study help with exploring the effects of land use structure under the goal-oriented control of air pollution and provide theoretical reference and decision-making support for formulating precise air pollution control policies and optimizing the spatial development of national land.