Integrating genomic data and simulations to evaluate alternative species distribution models and improve predictions of glacial refugia and future responses to climate change

Climate change poses a threat to biodiversity, and it is unclear whether species can adapt to or tolerate new conditions, or migrate to areas with suitable habitats. Reconstructions of range shifts that occurred in response to environmental changes since the last glacial maximum from species distribution models (SDMs) can provide useful data to inform conservation efforts. However, different SDM algorithms and climate reconstructions often produce contrasting patterns, and validation methods typically focus on accuracy in recreating current distributions, limiting their relevance for assessing predictions to the past or future. We modeled historically suitable habitat for the threatened North American tree green ash (Fraxinus pennsylvanica) using 24 SDMs built using two climate models, three calibration regions, and four modeling algorithms. We evaluated the SDMs using contemporary data with spatial block cross-validation and compared the relative support for alternative models using a ..., , , # Integrating genomic data and simulations to evaluate alternative species distribution models and improve predictions of glacial refugia and future responses to climate change

[https://doi.org/10.5061/dryad.s7h44j1fx](https://doi.org/10.5061/dryad.s7h44j1fx)

This repository contains analysis scripts and input data files associated with the integrated distributional, demographic, and coalescent (iDDC; He et al. 2013) modeling analysis conducted to compare alternative species distribution models (SDMs) for green ash (*Fraxinus pennslvanica*) in Naugthin et al. (2024) *Ecography*.

## Description of the data and file structure

Simulations for the project were conducted using the R script `hSC_Ash_with_enms.R`.  This script uses the R package holoSimCell (available from [https://github.com/stranda/holoSimCell](https://github.com/stranda/holoSimCell) to simulate post-glacial expansion of green ash in eastern North America.  We also include the singularity (now apptainer, [https://apptain...