Asymptotic properties of branching processes in random environment

Let (Z(n)) be a branching process in a random environment. If the process in sub-critical or critical, we study the convergence rate of the survival probability P(Z(n) > 0) as n --> infinity: if the process is supercritical, we give a necessary and sufficient condition for the convergence in L-P of the natural martingale, where p > 1 is given. (C) 2001 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.