Comparative assessment of biodiversity conservation effectiveness across protected areas through considering both...

Protected areas are regarded as a foundational strategy for biodiversity conservation. However, equitable frameworks for assessing their effectiveness across regions are still lacking, which limits informed allocation of conservation funding. To address this, we developed a method to compare biodiversity outcomes across regions with varying ecological baselines under different levels of management effort. The approach uses habitat quality as a proxy for biodiversity and accounts for human-induced habitat changes. Each region is benchmarked against its ecological background, allowing conservation outcomes to be assessed relative to local conditions. By integrating these elements, we construct an index of conservation effectiveness that enables fair and meaningful regional comparisons. The proposed approach was applied to a regionally comparative assessment of conservation effectiveness across 63 Important Ecological Functional Areas in China. The results indicate that (1) The human-induced habitat quality index proved to be an effective indicator for distinguishing between natural and anthropogenic influences on habitat conditions. (2) The reference condition index serves as an effective indicator of conservation capacity across different ecological functional areas. (3) The conservation effectiveness index facilitates the comparability of biodiversity conservation effectiveness across regions. Among the diverse types of IEFAs, sandstorm prevention areas deliver the most pronounced biodiversity conservation outcomes. This is closely trailed by flood regulation and storage zones, whereas soil retention areas exert the least significant influence. Important Ecological Functional Areas located west of the Hu Huanyong Line generally exhibit higher conservation effectiveness than those situated to the east. This study highlights the importance of integrating both management efforts and underlying ecological contexts into funding allocation strategies, providing a scientific foundation for China's transfer payment policy and offering guidance for the distribution of biodiversity conservation funds in other countries.