Simulation and analysis of an individual-based model for graph-structured plant dynamics

We propose a stochastic individual-based model of graph-structured population, viewed as a simple model of clonal plants. The dynamics is modeled in continuous time and space, and focuses on the effects of the network structure of the plant on the growth strategy of ramets. This model is coupled with an explicit advection-diffusion dynamics for resources. After giving a simulation scheme of the model, the capacity of the model to reproduce specific features of clonal plants, such as their efficiency to forage resources and colonize an empty field by means of phalanx or guerrilla strategies, is numerically studied. Next, we propose a large population approximation of the model for phalanx-type populations, taking the form of an advection-diffusion partial differential equation for population densities, where the influence of the local graph structure of the plant takes the form of a nonlinear dependence in the gradient of resources. (C) 2012 Elsevier BM. All rights reserved.