Predictive ability of a process‐based versus a correlative species distribution model

Abstract

Species distribution modeling is a widely used tool in many branches of ecology and evolution. Evaluations of the transferability of species distribution models—their ability to predict the distribution of species in independent data domains—are, however, rare. In this study, we contrast the transferability of a process‐based and a correlative species distribution model. Our case study uses 664 Australian eucalypt and acacia species. We estimate models for these species using data from their native Australia and then assess whether these models can predict the adventive range of these species. We find that the correlative model—MaxEnt—has a superior ability to describe the data in the training data domain (Australia) and that the process‐based model—TTR‐SDM—has a superior ability to predict the distribution of the study species outside of Australia. The implication of this analysis, that process‐based models may be more appropriate than correlative models when making projections outside of the domain of the training data, needs to be tested in other case studies.

A problem with variable selection in a comparison of correlative and process‐based species distribution models: Comments on Higgins et al., 2020

“…If there are gross differences, this suggests more variables may be needed or that the variables being used may not be appropriate. Higgins et al, (2020) is potentially a very interesting paper, but the Köppen-Geiger classification, the Thompson et al, (2011) paper, and the ALA analysis described here clearly indicate that there is a fundamental problem with the MaxEnt analyses as illustrated by Thompson et al, (2011). Green-yellow areas are climatically suitable and reddish-brown areas are highly suitable.…”

“…The Higgins et al, (2020) paper analyzed natural distribution data for 664 Australian eucalypt and acacia species. Natural distribution data for 46 selected species were also analyzed to assess whether a process-based or a correlative SDM most effectively predicted the adventive range of these species outside Australia.…”

“…Higgins et al, (2020) provided an example of their comparative analyses in their Figure 5. The top map in this figure shows "global projected environmental suitability" based on a MaxEnt analysis of the natural distribution of Acacia saligna in Western Australia.…”

“…Figure5in theHiggins et al, (2020) paper. It is hoped that the authors will be able to repeat their analyses using BIOCLIM variables with the MaxEnt model.…”

Transferability of correlative and process‐based species distribution models revisited: A response to Booth

“…We welcome the critique of our recent contribution to Ecology and Evolution (Higgins et al, 2020) by Dr Booth (Booth, 2021), and in this response, we take the opportunity to show that his concerns are unfounded and miss the point of Higgins et al (2020). We begin by responding directly to the claims made in Booth's letter (Booth, 2021).…”