Implications of environmental fluctuations for establishment probability

Patsy Haccou

Theoretical Biology, University of Leiden, Netherlands

Abstract

Establishment succes in fluctuating environments is studied by means of inhomogeneous branching process models. An important difference between constant and fluctuating environments is that, whereas in a constant environment the probability of a successful invasion is fixed and does not vary over time, in a fluctuating environment the fate of a newly arrived individual strongly depends on the timing of invasion. Since there is a large probability of extinction in the first generations, an invasion in a favourable period has a much higher chance of eventual success than an invasion during an unfavourable period. One of the major implications of this phenomenon is that sequential invasions have a higher probability of success than simultaneous ones. This has large consequences for invasion strategies, biological control strategies, and metapopulation dynamics.