  An individual-based model (IBM) of a spatiotemporal terrestrial ecological
population is proposed. This model is spatially explicit and features the
position of each individual together with another characteristic, such as the
size of the individual, which evolves according to a given stochastic model.
The population is locally regulated through an explicit competition kernel. The
IBM is represented as a measure-valued branching/diffusing stochastic process.
The approach allows (i) to describe the associated Monte Carlo simulation and
(ii) to analyze the limit process under large initial population size
asymptotic. The limit macroscopic model is a deterministic integro-differential
equation.
