Fugitive Coexistence in Sessile Species: Models with Continuous Recruitment and Determinate Growth

I previously developed a model of growth and competition in sessile organisms, which I used to show that the sized of patches caused by disturbance could have an important effect on species diversity. When disturbance patch size is small, new individuals will be recruited from patches of many different ages and in different successional stages, such "regional" recruitment promotes coexistence. In contrast, when disturbance patch size is large and recruitment involves only individuals from a single successional stage, coexistence becomes less likely. That model contained the rather restrictive assumptions (1) that individuals grow radially at constant speed and (2) that all recruitment occurs in a short period of time following disturbance. In this paper I replace these assumptions with ones that allow for limited (determinate) growth to a fixed upper size; I also allow continuous recruitment from a well—mixed "reigonal" source. My conclusions are (1) that coexistence should be easier, and so diversity should be higher, in communities of organisms with determinate growth than in communities of organisms with indeterminate growth and (2) that continuous recruitment decreases the probability of coexistence.