Biodiversity primarily drives the spatial stability of ecosystem functions and multifunctionality, along with biotic and abiotic factors across South Korean forests

Introduction Maintaining the stability of forest ecosystem functions and mitigating climate-driven declines in ecosystem multifunctionality (EMF) are central objectives of contemporary forest management. Methods We evaluated the spatial stability of 11 forest ecosystem functions and overall multifunctionality using data from 2,859 natural forest plots in South Korea’s 7th National Forest Inventory. Specifically, we investigated how biotic factors (species, functional, and structural diversity), abiotic factors (elevation and aridity), and stand age influence the spatial stability of EMF and individual functions. Variance partitioning and regression analyses were conducted to determine the relative contributions of these factors. Results Biodiversity-related biotic factors—particularly species richness and structural diversity—were the main determinants of spatial stability for most individual functions and multifunctionality, generally showing positive effects. However, these relationships varied among different functions. Among abiotic variables, higher elevations and lower water stress (i.e., a higher aridity index) were associated with greater stability. In addition, community-weighted means of functional traits influenced EMF, with maximum tree height showing a particularly strong link to multifunctionality and its stability. Discussion Overall, our findings underscore the importance of developing targeted management strategies to enhance EMF and individual ecosystem functions. They further suggest that biodiversity alone does not guarantee stability across all ecosystem functions, highlighting the need to consider both biotic and abiotic contexts in forest management planning.