“Canonical” Ecological Niche Modeling

Google “Species Distribution Model”

The Essence of the Method

• Use primary occurrence data• Use raster environmental data sets• Combine the two data streams in a model• Use the model to make a map• Map is interpreted as “probability of

presence” of the species

• It’s simple, right?

It’s More Complicated…• Accumulate input data• Data quality – occurrence data• Data quality – environmental data• Consistency between occurrence data and

environmental data• Check biogeographic/ecological scenario• Choose area for model calibration• Calibrate the model• Model evaluation• Check model extrapolation• … NOW, you can interpret your model

Assess levels of spatial autocorrelation in environmental data, adjust input point data accordingly

Estimate ecological niche (various algorithms)

Evaluation reality of model transfer results, when possible

Transfer to other situations—time and space

Project niche model to geographic space

Model calibration, adjusting parameters to maximize quality

Collate primary biodiversity data documenting occurrences

Process environmental layers to be maximally relevant to distributional ecology of species in question

Collate GIS database of relevant environmental data layers

Assess BAM scenario for species in question; avoid M-limited situations

Saupe et al. 2012. Variation in niche and distribution model performance: The need for a priori assessment of key causal factors. Ecological Modelling, 237–238, 11-22.

Estimate M as area of analysis in study

Barve et al. 2011. The crucial role of the accessible area in ecological niche modeling and species distribution modeling. Ecological Modelling, 222, 1810-1819.

Assess extrapolation (MESS and MOP)

Owens, H. L., L. P. Campbell, L. L. Dornak, E. E. Saupe, N. Barve, J. Soberón, K. Ingenloff, A. Lira-Noriega, C. M. Hensz, C. E. Myers, and A. T. Peterson. 2013. Constraints on interpretation of ecological niche models by limited environmental ranges on calibration areas. Ecological Modelling 263:10-18.

Model evaluationPeterson et al. 2008. Rethinking receiver operating characteristic analysis applications in ecological niche modelling. Ecological Modelling, 213, 63-72.

Model thresholdingPeterson et al. 2007. Transferability and model evaluation in ecological niche modeling: A comparison of GARP and Maxent. Ecography, 30, 550-560.

Assess spatial precision of occurrence data, adjust inclusion of data (obs and env) accordingly

General Methodological Summary: Peterson et al. (2011) Ecological Niches and Geographic Distributions, Princeton University Press, Princeton.

Refine estimate of current distribution via land use, etc.

Reduce dimensionality

Compare present and future to assess effects of change

Qiao, H., J. Soberón, and A. T. Peterson. 2015. No silver bullets in correlative ecological niche modeling: Insights from testing among many potential algorithms for niche estimation. Methods in Ecology and Evolution 6:1126-1136.