Stage-Structured Integro-Differential Models: Application to Invasion Ecology
Modelling dispersal processes requires a quantitative measure of the amount of individuals dispersed at each distance, which is conveniently summarized in a dispersal kernel. The framework of stage-structured integro-differential models provides spatially explicit population dynamics models that couple a stage-structured life-cycle with a dispersal kernel. This framework is flexible and can notably incorporate density-dependence and stochasticity in demography and dispersal. We first present the general formalism of stage-structured integro-differential models and then provide two examples of application, both from invasion ecology. The first model was developed for the spread of feral oilseed rape along road verges. It is a one-dimensional deterministic invasion model, with a complex dispersal kernel that includes the combined action of various dispersal vectors. The second model was developed for the invasion of grasslands by pines and is a two-dimensional stochastic model with a life-cycle that accounts for the maturity age (10 years) and the dependence of cone production to tree height and tree density.