Introduction to Stage-Structured Population Models

Abstract

The core of most integrated population models is a stage-structured (or matrix) population model, which provides the linkage between the demography of individuals and the trajectory of a population. We give a concise summary of the traditional analysis of matrix population models and emphasize the connection between matrix and integrated population models. We explain how knowledge about the demography of a study species leads to life-cycle graphs and ultimately to population equations. In this mathematical formalization of population dynamics, several key decisions must be made such as choosing the “census” period and structuring the population into age or stage classes. Matrix population models are parameterized with demographic rates, and we show how population growth rates and life-history summaries can be computed using R and JAGS. The latter software is particularly useful for complex models that include demographic and environmental stochasticity or parameter uncertainty. Formulation of matrix population models in JAGS leads naturally to integrated population models.