Equilibrial model of community dynamics
- The classic model which states that communities are in equilibrium
- Species abundance remains constant over time - it is in a state of stable equilibrium
- Stability can be measured by the time it takes to recover from disturbance. Stable communities recover quickly from disturbances.
- Stability can also be measured by the variability of a community, if the community structure remains constant over time then it is stable. It can be a measure of the persistence of a community.
- Such a community would have many biotic interactions involving predation and competition.
- Such communities would be saturated in species richness, meaning that it holds the maximum possible number of species. This means that invasions are rare.
- Rarely weather catastrophes occur in these communities.
Nonequilibrial model of community dynamics
- By contrast this model states that communities would score low on all the above measures of stability.
- Extreme weather events would occur frequently in these systems.
Real communities are spread along an spectrum from equilibrium to nonequilibrium