An ecosystem is considered collapsed when its unique biological and other natural features are lost from all previous occurrences.Ecosystem collapse could be reversible and is thus not completely equivalent to species extinction.1
Ecosystem collapse can lead to catastrophic declines of carrying capacity and mass extinction (known as ecological collapse), and can also pose existential risk to human populations.
Despite the strong empirical evidence, anticipating collapse is a complex problem. The collapse can happen when the ecosystem’s distribution decreases below a minimal sustainable size, or when key biotic processes and features disappear due to environmental degradation or disruption of biotic interactions. These different pathways to collapse can be used as criteria for estimating the risk of ecosystem collapse. Although states of ecosystem collapse are often defined quantitatively, few studies adequately describe transitions from pristine or original state towards collapse.