Ecological spatial network optimization of carbon sink patches for enhanced carbon sink in Wuhan Metropolitan Area, China

Achieving carbon neutrality through increasing carbon sinks is a crucial strategy for reaching long-term climate objectives. During rapid urbanization, the degradation of vegetation structure and quantity in fragmented patches leads to the reduction of the carbon sink capacity. Establishing the well-design ecological spatial network is crucial for improving the carbon sink capacity. This study focuses on enhancing the carbon sink capacity in the Wuhan Metropolitan Area (WMA) through a four-step approach-identification, construction, assessment, and optimization-to improve the ecological spatial structure of carbon sink patches and increase carbon sink capacity. The results show that we initially built 27 carbon sink patches and 52 networks, prioritizing 15 core networks. Due to the low connectivity between the Western and other regions, we added 18 steppingstones and 12 networks to enhance overall connectivity and stability of spatial network. Verification shows that our scheme benefits the connectivity and stability of whole ecological network of WMA, and increases the total carbon sink by 11.17 Mt CO2. This research enriches methods for increasing carbon sinks in urban areas and provides theoretical support for achieving carbon neutrality.