Calculation of carbon sequestration capacity and optimization of design strategies for pocket parks in high-density urban areas under the dual carbon goals: a case study of rihui green space in Xuhui District, Shanghai

Under the impetus of the "dual carbon" goals, the construction of low-carbon landscapes in small and micro green spaces in urban central areas has become a key path to balance high-density built environments and ecological benefits. This paper focuses on the Rihui Green Space Pocket Park in Xuhui District, Shanghai, and addresses the issues of insufficient carbon sequestration capacity and the absence of carbon management mechanisms in small green spaces in high-density urban areas. Guided by the concept of "carbon neutrality", a full life-cycle carbon accounting model for pocket parks is constructed to quantify their carbon sequestration capacity. Optimization strategies are proposed through increasing carbon sequestration and reducing carbon emissions to achieve carbon balance in pocket parks. The research finds that for pocket parks of this type of small green spaces, their main carbon sequestration capacity comes from plants, so the selection of native carbon-fixing plants is crucial for increasing the annual carbon sequestration capacity of pocket parks; the use of low-carbon materials and the recycling of waste building materials can reduce carbon emissions during the construction period; the integration of photovoltaic power generation and landscape design can reduce operational energy consumption; optimizing spatial design and improving the permeability of pavement can achieve carbon reduction throughout the life cycle. The research further proposes multi-dimensional collaborative strategies: ①integration of low-carbon technologies, including the application of renewable energy and bioretention facilities; ②optimization of vegetation communities, by selecting native plant combinations with high carbon sequestration and low maintenance; ③community co-construction mechanisms, guiding public participation through carbon account management and low-carbon activities; ④establishing a micro carbon data monitoring platform for pocket parks. using machine learning to predict changes in green space carbon sequestration capacity, and achieving a decision-making combination of carbon flow data and landscape facility operation and maintenance. The practice of Rihui Green Space shows that the low-carbon construction of small and micro green spaces can enhance ecological benefits through refined carbon management, providing a quantifiable and replicable "design-technology-governance" integrated model for the low-carbon transformation of similar urban pocket parks, and assisting in the local realization of the carbon neutrality goals in high-density cities.