Discrepancies in cropland mapping and their implications for biodiversity conservation in China

The increasing public availability of long-term remote sensing imagery, combined with advancements in algorithms and cloud computing, has enabled the development of large-scale cropland mapping datasets at national and global levels. These datasets are critical for assessing the ecological and environmental risks of agricultural production in the Anthropocene era. While previous studies have primarily focused on improving the accuracy of cropland mapping, the implications of dataset discrepancies for evaluating cropland-induced ecological impacts remain insufficiently explored. Here, we integrate seven publicly available cropland datasets covering China and systematically analyze their spatiotemporal discrepancies, along with associated uncertainties in assessing habitat and biodiversity impacts. Our analysis incorporates key conservation areas, protected zones, species richness maps, and Dynamic Habitat Indices time series data. The results indicate that although all datasets indicate a general stabilization of cropland area in China over recent decades, significant discrepancies persist—particularly at finer spatial scales and in ecologically sensitive regions. These discrepancies not only influence the diagnosis of spatial conflicts between cropland and habitat areas but may also result in an underestimation of the threats posed by cropland expansion to habitats of threatened species. Furthermore, regions with greater cropland mapping discrepancies tend to exhibit lower environmental stability. Our findings highlight the need for selecting regionally appropriate cropland datasets when assessing historical and current cropland distributions and their ecological consequences. This study also offers insights into how remote sensing technologies can be better leveraged for ecological and agricultural sustainability research.