Trade-off or synergy? Dynamic analysis and policy insights on land use functions in China

Limited land resources and diverse utilization have resulted in complex trade-offs and synergies (TS) among land use functions (LUFs). Analyzing these TS and their spatio-temporal variations is crucial for developing effective land use policies to regulate and manage multiple LUFs, promoting efficient land resource utilization and fostering sustainable development in society, economy, and ecology. This study uses interdisciplinary research methods, including the projection pursuit model, Spearman's rank correlation analysis, and exploratory spatial data analysis, to investigate the characteristics of LUFs TS in 31 provincial administrative divisions in China from 2009 to 2020. Key findings include: (1) LUFs exhibited significant spatial heterogeneity and temporal variations. Most LUFs experienced distinct upgrading processes, except for SSF (Social Security Function), which requires specific attention.(2) LUFs TS were found to be common and consistent, with varying characteristics observed in different years. It is crucial to consider these characteristics during the process of functional regulation to enhance effectiveness. (3) We confirmed that LUFs, as a public service, show substantial spatial spillover effects, resulting in cross-regional LUFs TS. Regulatory strategies should harness the radiating and propelling effects of advantageous functions while maintaining equilibrium and coordination in regional development, ultimately achieving optimal overall benefits. Finally, we discuss the study findings in comparison with existing research and provide policy insights to promote the harmonized and sustainable development of LUFs. These findings aim to serve as a scientific foundation for land use planning and management in China and offer valuable insights for other regions.