Extinction threshold of a population in spatial and stochastic model

Abstract: In this study, spatial stochastic and logistic model (SSLM) describing dynamics of a population of a certain species was analysed. The behaviour of the extinction threshold as a function of model parameters was studied. More specifically, we studied how the critical values for the model parameters that separate the cases of extinction and persistence depend on the spatial scales of the competition and dispersal kernels. We compared the simulations and analytical results to examine if and how the mathematical approximations break down at the vicinity of the extinction threshold, and found a functional form of the naive approximation for which higher-order term of analytical approximation converges.