Spatiotemporal Evolution Analysis and Optimization Strategy Development for Ecological Carbon-Sink Security Patterns: A Case Study of Zhengzhou, China

Carbon sinks have been widely recognized as critical components of climate change mitigation and achieving carbon neutrality. With rapid urbanization, protecting and optimizing urban carbon sinks remain major challenges. This study uses Zhengzhou as a case study and analyzes 2000–2023 land-use data with the InVEST model to quantify carbon stocks and identify high-value carbon-sink areas. Circuit theory was further integrated to delineate ecological security patterns and inform optimization strategies. The results show a net decrease of 19.12 × 10 6 t in carbon storage from 2000 to 2023, with the most rapid decline occurring during 2015–2020. Spatially, high-value carbon storage clustered in forested, high-elevation areas in the southwest, whereas low values predominated in the urban core. Carbon-sink source areas continued to shrink: fragmentation increased in the east, the west remained relatively stable, and the central area was highly fragmented. Corridor analysis indicated that the mean corridor length first increased and then decreased, accompanied by an expansion of pinch points and barrier areas. The study developed a systematic optimization framework that establishes a “Two Cores, Five Carbon-Sink Areas, Multiple Corridors” security pattern and proposes targeted conservation measures. The proposed methodology and findings offer a transferable basis for managing urban carbon sinks in rapidly developing regions and support both ecological security and climate-change mitigation, promoting sustainable urban development.