Colonisation or colonization is the spread and development of an organism in a new area or habitat. Colonization comprises the physical arrival of a species in a new area, but also its successful establishment within the local community. In ecology, it is represented by the symbol λ (lowercase lambda) to denote the long-term intrinsic growth rate of a population.
Surrounding theories and applicable process have been introduced below. These include dispersal, colonisation-competition trade off and prominent examples that have been previously studied.
One classic scientific model in biogeography posits that a species must continue to colonize new areas through its life cycle (called a taxon cycle) in order to persist. Accordingly, colonisation and extinction are key components of island biogeography, a theory that has many applications in ecology, such as metapopulations. Another factor included in this scientific model is the competition-colonisation trade off. This idea goes into the driving factors of colonisation through many species that all share a need to expand.