sdm: a reproducible and extensible R platform for species distribution modelling

variables (e.g. whether predictor contributions are weighted, and whether they allow for interactions among variables) (Segurado and Araújo 2004, Elith et al. 2006, Austin 2007, Naimi et al. 2011, Peterson et al. 2011). The outputs of SDMs are sensitive to the specific rules used to parameterize them. When models are implemented in different platforms, rules used to fit them may not be comparable. For example, Domain (Carpenter et al. 1993), DesktopGARP (Stockwell and Peters 1999), and Maxent (Phillips et al. 2006) are typically implemented with different off-the-shelf software making cross-model comparisons challenging. Models are also generally implemented following different protocols for pre-processing of data and postprocessing of the results, even when they are implemented within the same computer platform. Given the difficulties in comparing the results of different models, conclusions from model comparison studies are difficult to generalise beyond the specific case studies (Segurado and Araújo 2004, Elith et al. 2006). An integrated framework enabling multiple SDMs to be fitted and compared simultaneously is required to move the field of species distribution modeling forward. Three off-theshelf software including openModeller (de Souza Muñoz et al. 2009), BIOENSEMBLES (Diniz-Filho et al. 2009), and ModeEco (Guo and Liu 2010) have been independently developed to provide such frameworks. They enable several modelling algorithms to be fitted simultaneously and they perform the most common tasks related to species Ecography 39: 368–375, 2016 doi: 10.1111/ecog.01881 © 2016 The Authors. Ecography © 2016 Nordic Society Oikos Subject Editor: Edmund Hart. Editor-in-Chief: Michael Borregaard. Accepted 27 January 2016