Journal Article

Model selection and information theory in geographical ecology

Bini, Luis Mauricio, Diniz-Filho, José Alexandre Felizola, Rangel, Thiago Fernando L.V.B

2008

Overview

Although parameter estimates are not as affected by spatial autocorrelation as Type I errors, the change from classical null hypothesis significance testing to model selection under an information theoretic approach does not completely avoid problems caused by spatial autocorrelation. Here we briefly review the model selection approach based on the Akaike information criterion (AIC) and present a new routine for Spatial Analysis in Macroecology (SAM) software that helps establishing minimum adequate models in the presence of spatial autocorrelation. We illustrate how a model selection approach based on the AIC can be used in geographical data by modelling patterns of mammal species in South America represented in a grid system (n = 383) with 2° of resolution, as a function of five environmental explanatory variables, performing an exhaustive search of minimum adequate models considering three regression methods: non-spatial ordinary least squares (OLS), spatial eigenvector mapping and the autoregressive (lagged-response) model. The models selected by spatial methods included a smaller number of explanatory variables than the one selected by OLS, and minimum adequate models contain different explanatory variables, although model averaging revealed a similar rank of explanatory variables. We stress that the AIC is sensitive to the presence of spatial autocorrelation, generating unstable and overfitted minimum adequate models to describe macroecological data based on non-spatial OLS regression. Alternative regression techniques provided different minimum adequate models and have different uncertainty levels. Despite this, the averaged model based on Akaike weights generates consistent and robust results across different methods and may be the best approach for understanding of macroecological patterns.

• Publisher: Oxford, UK : Blackwell Publishing Ltd,Blackwell Publishing Ltd,Blackwell Publishing,Blackwell
• Subject: Animal and plant ecology / Animal, plant and microbial ecology / Applied ecology / Autocorrelation / Biogeography / Biological and medical sciences / Ecological genetics / Ecological modeling / Ecological selection / ecology / Fundamental and applied biological sciences. Psychology / General aspects / least squares / Macroecological Methods / mammals / Modeling / Parametric models / South America / Spatial models / Species / Synecology / uncertainty