A systematic analysis and review of soil organic carbon stocks in urban greenspaces

• Published in: The Science of the total environment Vol. 948; p. 174788
• Main Authors: Guo, Yang, Han, Jiatong, Bao, Haijun, Wu, Yuzhe, Shen, Liyin, Xu, Xiangrui, Chen, Ziwei, Smith, Pete, Abdalla, Mohamed
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20.10.2024
• Subjects: carbon sequestration; clay fraction; Climate; environment; green infrastructure; Human footprint; humans; Management and environmental setting; Selected soil properties; soil density; soil depth; Soil organic carbon; standard deviation; turf grasses; urban forests; Vegetation type; wetlands; Climate; Vegetation type; Selected soil properties; Soil organic carbon; Management and environmental setting; Human footprint
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.174788

Urban greenspaces typically refer to urban wetland, urban forest and urban turfgrass. They play a critical role in carbon sequestration by absorbing carbon from the atmosphere; however, their capacity to retain and store carbon in the form of soil organic carbon (SOC) varies significantly. This study provides a systematic analysis and review on the capacity of different urban greenspace types in retaining and storing SOC in 30 cm soil depth on a global scale. Data came from 78 publications on the subject of SOC stocks, covering different countries and climate zones. Overall, urban greenspace types exerted significant influences on the spatial pattern of SOC stocks, with the highest value of 18.86 ± 11.57 kg m−2 (mean ± standard deviation) in urban wetland, followed by urban forest (6.50 ± 3.65 kg m−2), while the lowest mean value of 4.24 ± 3.28 kg m−2 was recorded in urban turfgrass soil. Soil organic carbon stocks in each urban greenspace type were significantly affected by climate zones, management/environmental settings, and selected soil properties (i.e. soil bulk density, pH and clay content). Furthermore, our analysis showed a significantly negative correlation between SOC stocks and human footprint in urban wetland, but a significantly positive relationship in urban forest and urban turfgrass. A positive correlation between SOC stocks and human footprint indicates that increased human activity and development can enhance SOC stocks through effective management and green infrastructure. Conversely, a negative correlation suggests that improper management of human activities can degrade SOC stocks. This highlights the need for sustainable practices to maintain or enhance SOC accumulation in urban greenspaces. [Display omitted] •SOC were highest in urban wetland, followed by urban forest, and lowest in turfgrass.•SOC exhibited positive correlation with human footprint in urban forest and turfgrass.•SOC stocks varied with climate, vegetation, environmental setting, soil bulk density.•Assessing SOC in urban greenspaces supports policy efforts to mitigate climate change.