Optimization of Ecosystem Service Bundles from a Trade-Off and Synergistic Perspective: A Case Study of Qinghai Province

Ecosystem services, encompassing the provision of food, water, air purification, climate regulation, and disease mitigation, form the bedrock upon which human well-being and socio-economic development are anchored. The preservation of these services is instrumental in safeguarding human survival and fostering progress. Qinghai Province, located on the Qinghai–Tibetan Plateau, holds a pivotal role as a crucial ecological barrier within China. The optimization of its ecosystem services is vital for the effective management of ecologically fragile areas. This study focuses on Qinghai Province. By integrating natural geographic, social, and Points of Interest (POI) big data, we utilized tools like InVEST, CASA, and advanced algorithmic optimizations to analyze ecosystem services and their trade-off synergies in Qinghai from 2000 to 2020. Based on these synergies, we developed a novel optimization algorithm to generate spatial bundles that amplify synergistic interactions while minimizing costs. Our findings indicate that the following: (1) Between 2000 and 2020, recreational services, water yield, and habitat quality in Qinghai Province generally exhibited an upward trend, whereas carbon sequestration showed a decline; (2) Notable synergies were evident between carbon sequestration and habitat quality and between recreation services and habitat quality. Conversely, significant trade-offs were observed between water yield and habitat quality and between water yield and cultural services, with these trade-off synergy effects varying markedly across different regions; (3) We constructed ecosystem service bundles characterized by “strong synergy–weak trade-off” based on these relationships. Following optimization, regions demonstrating significant synergies expanded, while those showing significant trade-offs contracted, thereby adapting to the ecological heterogeneity of high-altitude areas. This study advances the optimization of ecosystem service bundles in ecologically sensitive zones through a lens of trade-off synergies. The results offer a scientific foundation for formulating effective ecological protection and restoration strategies, providing valuable insights for ecosystem service research in other high-altitude regions globally.