In ecology, it is represented by the symbol λ (lowercase lambda) to denote the long-term intrinsic growth rate of a population.
Accordingly, colonisation and extinction are key components of island biogeography, a theory that has many applications in ecology, such as metapopulations.
Often times species naturally disperse due to physiological adaptations which allows for a higher survival rate of progeny in new ecosystems.
Other times these driving factors are environmentally related, for example global warming, disease, competition, predation.
The competition-colonisation trade-off refers to a driving factor that has a large influence over diversity and how it is maintained in a community.