Enhancing the carbon sequestration potential of urban green space: A water–energy–carbon fluxes perspective

Regulating carbon emissions during landscape maintenance is crucial for increasing net carbon sequestration in urban green spaces. This research focuses on balancing water and energy resource conservation with increasing carbon sequestration. We introduced an integrated water–energy–carbon (WEC) fluxes framework to evaluate the net carbon sequestration of green spaces and a water–energy–carbon sustainability index (WECSI) was developed to assess overall sustainability, emphasizing the carbon sequestration potential (CSP). Taking five types of urban green spaces at Zhejiang Agriculture and Forestry University as a case study, we observed significant differences in the WEC fluxes among the green space types. Specifically, mainly arbors and closed green space (AC) types had greater CSP due to scale effects, whereas mainly successional short grass and open green space (SGO) types were at risk of becoming net carbon sources. The WECSI analysis revealed the difficulties in simultaneously achieving water conservation, energy efficiency, and net carbon sequestration, with an average sustainability score of 0.57. To maximize CSP in urban green spaces, scenario analysis indicated that low-carbon irrigation practices could increase CSP by up to 25 %, whereas biomass energy from garden waste could reduce irrigation-related carbon emissions by 19 %. These findings provide a strong foundation for optimizing urban green space management to maximize CSP through WEC fluxes regulation.