A review of agroforestry biodiversity-driven provision of ecosystem services and implications for karst desertification control

Biodiversity conservation is critical for sustaining ecosystem services (ES) and preventing ecological degradation. In ecologically fragile environments, agroforestry (AF) plays a crucial role. This study aims to provide a comprehensive overview of biodiversity and ES in AF systems (AF-BES) to enhance the service capacity in karst desertification areas through protection and management strategies. We conducted a systematic review to elucidate how biodiversity within AF contributes to ES. The results demonstrate that AF shows diversity and stability at the taxonomic level, aggregation and internal adaptability at the functional level, and comprehensive, persistent, and environmentally complementary service characteristics. Regarding the relationship between biodiversity and ES, taxonomic diversity is the most commonly used substitute indicator of biodiversity, and functional indicators are rarely considered. Furthermore, the relationship between cultural services and biodiversity has not yet been established, although most empirical evidence shows a linear correlation. Future research should focus on functional diversity, immaterial services, and integrated quantification methods. This work advances our understanding of AF-BES and informs global biodiversity protection efforts, providing a foundation for restoring similar fragile ecosystems.