Integrating complexity in population modelling: From matrix to dynamic models

Matrix models are widely used in population ecology studies and are valuable for analysing population dynamics, although they are limited in the use of time-varying parameters. This limitation can be overcome by dynamic models. In this study, we revisit a previously published study on a matrix model of a population of the box jellyfish Carybdea marsupialis (L. 1758) in the Western Mediterranean. A dynamic model integrating the transition matrix of the original model is developed in STELLA Architect with the following improvements: (1) Sensitivity study of the reliability of the methodology for calculating the transition matrix and estimation of the errors of the fitting parameters; (2) Closure of the jellyfish life cycle by adding the polyp stage. This will make it possible to simulate scenarios of ecological interest over several years such as a decline in food supply, jellyfish removal strategies, changes in drift currents and changes in substrate availability for planulae to settle. (3) The inclusion of more biological reality. In particular, a temporal pattern of strobilation is added, which improves the fit of the model to the field data. • From values of the transition matrix, we built a dynamic model incorporating more biological-based reality with a higher flexibility in generating scenarios. • We calculated the transition matrix with error estimates for a time series data of the box jellyfish Carybdea marsupialis in W. Mediterranean. • The model evolved from a matrix model to a more general dynamical system with time-varying coefficients. • Can be useful to integrate more biological complexity into population models and obtain a better fit to the field data.