When an ecological threshold has been passed, the ecosystem may no longer be able to return to its state by means of its inherent resilience.
Zone-type thresholds imply a gradual shift or transition from one state to another rather than an abrupt change at a specific point.
[2] Ecological thresholds have caught attention because many cases of catastrophic worsening of conditions have proved to be difficult or nearly impossible to remedy (also known as points of no return).
Sudden shifts in ecosystem state can induce changes in human understanding of the way the systems need to be managed.
The thresholds database[4] by Resilience Alliance and Santa Fe Institute includes over one hundred examples.