Mediating role of food web structure in linking diversity to multidimensional stability: Evidence from global marine ecosystems

The diversity-stability relationship persists as a central ecological debate, as existing work primarily examines direct diversity and structural drivers, while empirical evidence clarifying how direct and structure-mediated pathways jointly shape ecosystem multistability remains limited. Here, we analyzed 217 global marine food webs, quantifying structural properties and multidimensional stability to evaluate how diversity and structure jointly influence stability. Our analyses reveal that diversity is consistently linked to stability through dual pathways: positively associated with resistance and resilience via indirect structural mediation, yet negatively correlated with local stability unless interaction strength is accounted for. Critically, omitting structural mediation yields a net negative diversity-stability correlation, whereas integrating food web structure uncovers context-dependent positive relationships, underscoring structural metrics as pivotal explanatory variables. Our findings reconcile the diversity-stability debate by showing that the food web structure mediates context-dependent stability outcomes-integrating direct and indirect pathways resolves contradictions and advances actionable metrics for conservation strategies resilient to environmental changes.