Mixture of inhomogeneous matrix models for species-rich ecosystems

Frederic Mortier (1) , Dakis-Yaoba Ouedraogo , Florian Claeys (2, 1) , Mahlet G. Tadesse (3) , Guillaume Cornu (1) , Fidele Baya (4) , Fabrice Benedet (1) , Vincent Freycon (1) , Sylvie Gourlet-Fleury (1) , Nicolas Picard (1)

1 UPR BSEF - Biens et services des écosystèmes forestiers tropicaux : l'enjeu du changement global
2 LEF - Laboratoire d'Economie Forestière
3 Department Mathematic and Statistic
4 MEFCP - Ministère Centrafricain des Eaux, Forêts, Chasses et Pêches

Understanding how environmental factors could impact population dynamics is of primary importance for species conservation. Matrix population models are widely used to predict population dynamics. However, in species-rich ecosystems with many rare species, the small population sizes hinder a good fit of species-specific models. In addition, classical matrix models do not take into account environmental variability. We propose a mixture of regression models with variable selection allowing the simultaneous clustering of species into groups according to vital rate information (recruitment, growth and mortality) and the identification of group-specific explicative environmental variables. We develop an inference method coupling the R packages flexmix and glmnet. We first highlight the effectiveness of the method on simulated datasets. Next, we apply it to data from a tropical rain forest in the Central African Republic. We demonstrate the accuracy of the inhomogeneous mixture matrix model in successfully reproducing stand dynamics and classifying tree species into well-differentiated groups with clear ecological interpretations. Copyright (c) 2014 John Wiley & Sons, Ltd.

Mots clés: usher models; species-rich ecosystems; lasso selection; mixture models; FUNCTIONAL-GROUPS; REGRESSION-MODELS; POPULATION-MODELS; VARIABLE SELECTION; TROPICAL RAIN-FORESTS; FINITE MIXTURES; GROWTH; DYNAMICS; CO2-INDUCED CLIMATE-CHANGE; GAP MODEL

Domaines: Sciences du Vivant [q-bio]

Frederic Mortier, Dakis-Yaoba Ouedraogo, Florian Claeys, Mahlet G. Tadesse, Guillaume Cornu, et al.. Mixture of inhomogeneous matrix models for species-rich ecosystems. Environmetrics, 2015, 26 (1), pp.39 - 51. ⟨10.1002/env.2320⟩. ⟨hal-01203839⟩