Mapping priority conservation areas for China's rice terraces: an integrated framework for identification and spatial prioritization

In the Anthropocene, traditional rice terraces have emerged as exemplary sustainable agro-ecosystems due to their dual functions in ecological conservation and cultural heritage. Systematically identifying the spatial distribution of Priority Conservation Areas (PCAs) is a prerequisite for mitigating abandonment risks and enabling effective conservation planning. Focusing on China's rice terraces, this study first developed a national 30 m resolution database by integrating multi-source geospatial data; then established a comprehensive evaluation framework encompassing six dimensions—livelihood, landscape, biodiversity, eco-service, culture, and social values; and finally employed the systematic conservation planning tool Marxan to identify the PCAs under 18 scenarios, with subsequent evaluation using multiple indicators. The results revealed that: (1) The total area of rice terraces in China is approximately 19.1 Mha, primarily distributed south of the Qinling–Huaihe Line, with the highest concentration in the Sichuan Basin. (2) The spatial patterns of PCAs vary across scenarios: cost-excluded scenarios lead to a more concentrated distribution, whereas cost-included scenarios result in a more dispersed pattern with a distinct eastward shift. The core PCAs are primarily clustered in several key regions: southern Zhejiang–northern Fujian, southern Anhui–northern Jiangxi, the Fujian–Guangdong–Jiangxi–Hunan junction, the Guizhou–Hunan–Guangxi junction, and southwestern Yunnan. (3) Regional analysis shows that Yunnan contains the largest number of PCAs, while Sichuan and Chongqing encompass the greatest total rice terrace area within these areas. Furthermore, Zhejiang and Fujian exhibit the highest share of rice terraces designated as PCAs relative to their provincial totals. This study maps China's rice terrace PCAs and demonstrates how regional heterogeneity and value orientation shape conservation outcomes, providing scientific guidance for tailored protection and restoration strategies.