Inhibition Model - Models of Succession
According to this model, succession is very heterogenous because the development at any one site depends on who gets there first. Species replacement is not necessarily orderly because each species tries to exclude or suppress any new colonists. Thus succession becomes more individualistic and less predictable because communities are not always converging at climatic climax. In this model, no species is competitively superior than another. Whoever colonises the site first holds it against all new comers.
Figure: Inhibition Model
Succession in this model proceeds from short-lived species to long-lived species and is not an orderly replacement. The essence of this model is that during succession, all replacements are possible, and much depends on who gets there first. The three models of succession agree that the pioneer species will appear first because these species have evolved certain colonising characteristic such as rapid growth, abundant seed production, and means of efficient dispersal. Early colonising species are not well adapted to establish in occupied sites, on account of root competition with the established species and the reduced availability of light. In the different models of succession, the early colonisers, are fugitive species that create conditions which makes the habitat progressively unsuitable for themselves.