My research interests are quite broad, but focus on the ecology and evolution of lichenized fungi and algae. In particular, I am especially interested in using molecular sequence data and phylogenetic analyses to address topics that are at the interface between ecology and evolution, such as the range of symbiotic associations and co-diversification between symbionts, as well as to better understand the evolution of various life history traits. My research has also concentrated on using lichens as indicators of air quality and forest health, as well as measuring historic changes in lichen communities. Finally, I am interested in lichen taxonomy, where my research has focused primarily on tropical and Great Lakes lichens as well as lichenized Basidiomycetes.