Stochastic matrix models for conservation and management: a comparative review of methods

Stochastic matrix models are frequently used by conservation biologists to measure the viability of species and to explore various management actions. Models are typically parameterized using two or more sets of estimated tra nsition rates between age/size/stage classes. While standard methods exist for analyzing a single set of transition rates, a variety of methods have b een employed to analyze multiple sets of transition rates. We review applic ations of stochastic matrix models to problems in conservation and use simu lation studies to compare the performance of different analytic methods cur rently in use. We find that model conclusions are likely to be robust to th e choice of parametric distribution used to model vital rate fluctuations o ver time. However, conclusions can be highly sensitive to the within-year c orrelation structure among vital rates, and therefore we suggest using anal ytical methods that provide a means of conducting a sensitivity analysis wi th respect to correlation parameters. Our simulation results also suggest t hat the precision of population viability estimates can be improved by usin g matrix models that incorporate environmental covariates in conjunction wi th experiments to estimate transition rates under a range of environmental conditions.