Elevational Range Impacts Connectivity and Predicted Deme Sizes From Models of Habitat Suitability

Area of Science:

• Ecology
• Evolutionary Biology
• Genetics

Background:

• Integrative distributional, demographic, and coalescent (iDDC) modeling is essential for understanding species' responses to environmental changes.
• A key component of iDDC is the statistical relationship between habitat suitability and local population sizes.
• Previous iDDC studies often assumed a linear relationship, potentially oversimplifying ecological dynamics.

Purpose of the Study:

• To explore the habitat suitability to population size relationship in two Brazilian Atlantic Forest Enyalius lizard species.
• To test if this relationship is nonlinear for high-elevation (E. iheringii) and linear for low-elevation (E. catenatus) species.
• To assess how nonlinear transformations affect spatiotemporal demographic inference and migration patterns.

Main Methods:

• Comparative analysis of iDDC models for Enyalius iheringii and E. catenatus.
• Hypothesis testing for linear versus nonlinear habitat suitability-population size relationships.
• Spatiotemporal demographic inference and effective migration estimation.

Main Results:

• Clear support for higher effective migration in E. iheringii compared to E. catenatus.
• Strong model support for a nonlinear habitat suitability-population size relationship in high-elevation E. iheringii.
• Weak support for a nonlinear relationship in low-elevation E. catenatus, but nonlinear models showed some improvement.

Conclusions:

• Accurate modeling of the habitat suitability-population size relationship is critical for robust iDDC inference.
• Nonlinear relationships can significantly influence spatiotemporal demographic predictions and genetic diversity patterns.
• Findings highlight the importance of species-specific ecological tolerances in demographic modeling.