Assessing the Regulatory Efficacy of National Key Ecological Function Zones on Ecosystem Service Balance

Balancing ecosystem service supply and demand is essential for regional sustainable development. The designation of National Key Ecological Function Zones (NKEFZs) serves as a critical policy tool to strengthen ecological regulation. This study evaluates four key ecosystem services-water provision, crop production, carbon storage, and habitat quality-in Hubei Province from 2005 to 2022, analyzing supply-demand surpluses and deficits, spatial-temporal dynamics, and the policy impact of NKEFZs using a staggered Difference-in-Differences (DID) approach. The results show that the supply-demand balance exhibits notable spatial heterogeneity: (1) water provision follows a "southern surplus-northern deficit" pattern, crop production and habitat quality show a "western surplus-eastern balance" structure, and carbon storage presents a "western surplus-eastern deficit" configuration. (2) Temporally, from 2005 to 2022, the water provision index rose from 0.12 to 0.30, crop production increased from 0.63 to 0.90, carbon storage declined from -0.03 to -0.38 despite a reduced deficit extent, and habitat quality remained stable though deficits expanded in eastern urban areas. (3) Comprehensive spatial-temporal analysis shows that surpluses are concentrated in western regions, while deficits dominate central and eastern cities, with most eastern and western areas improving, in contrast to declining trends in central cities; the province-wide average index rose from 0.45 to 0.51. (4) The DID results confirm that 2 / 38 the NKEFZs policy significantly improved the balance of ecosystem services, with the effect remaining robust after multiple tests. This study offers a scientific basis for optimizing ecological protection policies and advancing sustainability through improved ecosystem service management.