The Impact of China's National Key Ecological Function Areas Policy on Ecosystem Service Enhancement

The evaluation of the effectiveness of ecological conservation policies is crucial for ensuring their successful implementation. China's national key ecological function areas (NKEFAs) policy is a massive conservation program designed to enhance ecosystem services (ESs) and maintain national ecological security. However, a comprehensive assessment of its effectiveness in enhancing ESs has been lacking. In order to fill this gap, this study used the propensity score matching and difference‐in‐differences (PSM‐DID) method to quantify the spatio‐temporal effects of the NKEFAs policy on dominant ESs across four functional areas (biodiversity maintenance areas, water conservation areas, soil conservation areas, and sand‐fixing areas) from 2000 to 2022. The results indicated that, spatially, the ESs enhancement in the four NKEFA types significantly exceeded non‐NKEFAs, confirming the overall spatial effectiveness of the policy. However, it was noteworthy that 34.53% of the samples were found to be ineffective, indicating considerable potential for optimizing the spatial management. Additionally, there was an uneven distribution of effectiveness levels among the 25 areas, with significant deficiencies observed in Hainan Island and the Altai region. Temporally, the improvement level of ESs accelerated after the policy's implementation (post‐2010), but the improvement effects in water conservation areas and soil conservation areas remained relatively weak. Our findings suggested that future management of NKEFAs should focus on systematic and multi‐objective design while also preventing excessive vegetation restoration having a trade‐off effect on water yield services. This study provides a novel methodological framework and empirical evidence for evaluating the effectiveness of large‐scale ecological protection policies.