Carbon sinks in urban public green spaces under carbon neutrality: A bibliometric analysis and systematic literature review

Urban green spaces play essential roles in regulating the global carbon cycle and reducing carbon dioxide (CO2) emissions. However, research on the carbon sequestration efficiency of urban public green spaces, which is closely related to the human settlement environment, has not received enough attention. Thus, we systematically analyzed the existing literature in the Web of Science core database using bibliometrics and network analysis combined with the CiteSpace visualization tool. The aim of this review was to elucidate the focus and development trend of research conducted between 2007 and 2022 on carbon sinks in urban public green spaces. Our results demonstrated that: 1) Numbers of related publications are increasing annually, indicating that the subject is receiving increasing global attention. Related research topics primarily focus on two aspects: carbon sink measurement methods and sustainable carbon sink design for urban public green spaces. 2) Methods for measuring and monitoring carbon sinks in the urban public green spaces include sample plot measurement, the assimilation method, the micrometeorological method, the remote sensing (RS) estimation method, and laboratory work. Most methods follow the forestry system approach and lack the methods and techniques to directly assess the carbon sink effectiveness of urban public green spaces. 3) Key factors affecting the carbon sink capacity of urban public green spaces are: plant species selection, plant community structure, green space characteristics, and maintenance management. 4) Future research should focus on encouraging public participation in the design of sustainable carbon sinks in urban public green spaces, advancing biodiversity research on carbon sinks in urban public green spaces, and enhancing the precision of measurements while addressing regional differences. This study contributes to the integration of research on the effectiveness of carbon sinks in urban public green spaces and provides a theoretical reference and guidance reduces prospective urban emission and achieves climate goals.