Acknowledgments: 
We thank the many collectors, volunteers, and herbarium curators who made the niche modeling work possible and are particularly grateful to Andrew Budden (Royal Botanic Gardens Kew) and Germinal Rouhan (Muséum National d’Histoire Naturelle, Paris). This study is based on work supported by an NSF Postdoctoral Research Fellowship in Biology to E.S.B. under Grant 1711950.

References:

Bates, D. et al. 2015. Fitting linear mixed-effects models using lme4. - Journal of Statistical Software in press.