Answer to Question #64872 in Ecology for Sanjukta Ghosh

Question

I was reading Information theory by Eleith, Odum and Golley from different sources, one of which was Funfamentals of ecology by Odum:
... autogenic succession usually begins with an unbalanced community metabolism, where gross production, P, is either greater than or less than community respiration, R, and proceeds towards a more balanced condition, where P=R. The rate of biomass production (B/P ) increases during sucession until a stabilised system is achieved, in which a maximum of biomass (or high information content) and symbiosis between organisms are maintained per unit of available energy flow.
The succession begins with P>R in autotrophic sucession and P<R in heterotrophic sucession.
I have tried to find explanatory texts both in this and other books without any success so my question is how's this balanced state achieved in both types of successions?