RELATIONSHIP BETWEEN ECOSYSTEM STABILITY AND BIOLOGICAL DIVERSITY: MECHANISMS, EVIDENCE, AND ECOLOGICAL IMPLICATIONS

Abstract: The relationship between biological diversity and ecosystem stability represents one of the most fundamental and debated topics in contemporary ecology. This review synthesizes current theoretical frameworks and empirical evidence to elucidate how species richness, functional diversity, and community composition collectively influence ecosystem resistance and resilience to perturbation. Drawing upon meta-analyses of experimental grassland systems, forest inventories, and marine communities, we examine three core mechanisms: the insurance effect, functional redundancy, and complementarity in resource use. Our synthesis reveals that greater biodiversity consistently enhances ecosystem stability through multiple non-exclusive pathways, particularly under conditions of environmental stochasticity. The portfolio effect, whereby diverse communities buffer against asynchronous species responses, emerges as a robust and cross-system stabilizing mechanism. However, we also highlight critical moderating factors — including trophic structure, spatial heterogeneity, and the identity of dominant functional groups — that can alter or override diversity-stability relationships. Findings from long-term field experiments corroborate the theoretical prediction that biodiversity loss fundamentally impairs ecosystem functioning, with cascading consequences for stability. We conclude with a discussion of implications for conservation policy and ecosystem management in the context of accelerating anthropogenic biodiversity loss.