Alternative Stable State Theory and Regime Shifts Glossary

Alternative Stable State

Also known as "regime". One out of multiple different forms of existence or organization for a system; the system may transition to any of its alternative states if the appropriate environmental conditions are met.

Ball-and-Cup Model

A conceptual model used to visualize and understand ecological resilience. This is outlined in detail in another module, however the visualization is of a ball, representing the current state of a system, on a 3D plane that has different “basins” or points at which there is concavity. This visualization is meant to represent the states a system is drawn to (the ball being drawn into a basin) and the potential for shifting from one state, or basin, to another with movement of the ball caused by perturbation.

Ecological Resilience

The capacity of a system to withstand disturbances without altering established processes, functions, and structures. This concept can be applied to other systems such as economies, governments, or companies, despite the term “ecological”. 


When a change in one aspect of a system causes a change in an earlier aspect of the same system, whether positive or negative, and can be self-reinforcing. For example, rising temperatures can cause ice cover to decrease through melting. This exposes more land to the sun, which heats up the land near the ice and causes more melting, creating a positive feedback loop.


The general idea that the path out of a situation is different from the path you took to get into the situation. This can occur in ecosystems. See lake eutrophication example in the resilience and hysteresis modules.


Also known as "Disturbance". An event or input to a system that causes a loss of the system’s capital. It may cause a regime shift. For example, wildfire in a forest, ocean acidification and coral reefs, woody encroachment in a grassland.

Regime Shift

Also known as Regime Change. The transformation of a system from one stable state to another. These changes often occur in response to disturbances. For example, a volcanic eruption on a Hawaiian island can shift a tropical forest ecosystem into bare volcanic rock.


The spatial or temporal dimension of an object or process, characterized by both grain and extent (Turner & Gardner, 2015)

Threshold of Change

Also known as "tipping point". The point at which a system shifts from one state to an alternative state.