The equilibrium assumption in estimating the parameters of metapopulation models

>1. The construction of a predictive metapopulation model includes three st eps: the choice of factors affecting metapopulation dynamics, the choice of model structure, and finally parameter estimation and model testing. 2. Unless the assumption is made that the metapopulation is at stochastic q uasi-equilibrium and unless the method of parameter estimation of model par ameters uses that assumption, estimates from a limited amount of data will usually predict a trend in metapopulation size. 3. This implicit estimation of a trend occurs because extinction-colonizati on stochasticity, possibly amplified by regional stochasticity, leads to un equal numbers of observed extinction and colonization events during a short study period. 4. Metapopulation models, such as those based on the logistic regression mo del, that rely on observed population turnover events in parameter estimati on are sensitive to the implicit estimation of a trend. 5. A new parameter estimation method, based on Monte Carlo inference for st atistically implicit models, allows an explicit decision about whether meta population quasi-stability is assumed or not. 6. Our confidence in metapopulation model parameter estimates that have bee n produced from only a few years of data is decreased by the need to know b efore parameter estimation whether the metapopulation is in quasi-stable st ate or not. 7. The choice of whether metapopulation stability is assumed or not in para meter estimation should be done consciously. Typical data sets cover only a few years and rarely allow a statistical test of a possible trend. While m aking the decision about stability one should consider any information abou t the landscape history and species and metapopulation characteristics.