Understanding how perturbations affect the stability of ecosystems is fundamental to the prediction of future biodiversity loss and to ensuring the reliable provision of ecosystem services. Ecological stability is multifaceted, incorporating multiple interrelated components that attempt to capture the dynamics of systems and their response to perturbations. Experimental studies, supported by new theoretical insights, indicate that relationships among the various components of stability tend to weaken when systems are perturbed. However, we lack understanding of the generality of this phenomenon in natural systems. To address this, we quantified relationships between multiple components of ecological stability in natural grassland systems from around the globe that were disturbed experimentally in a variety of ways, by enrichment with different combinations of nutrients and / or reductions in grazing pressure.
We found that relationships between stability components weakened – and that stability thereby became more complex and less predictable – when grassland systems were perturbed. Moreover, this finding was consistent across all perturbation treatments applied. These results indicate clearly that the decoupling of ecological stability in perturbed systems is a globally important phenomenon in nature. This highlights the importance of quantifying multiple components of stability simultaneously and has profound implications for our understanding of the capacity for global change to destabilize ecosystems.