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Evolutionary and ecological consequences of mycorrhizal states in plants

PI(s): Brad Oberle (George Washington University)
Start Date: 12-Aug-2013
End Date: 1-Sep-2013
Keywords: comparative methods, biodiversity, macroevolution

Mycorrhizae are among the most ubiquitous and important mutualistic relationships in nature, but their evolutionary dynamics are poorly understood. Early land plants and most species today form arbuscular mycorrhizae (AM) with Glomeromycete fungi but some lineages have evolved distinctive ectomycorrhizae (EM) with Basidiomycetes and others from no mycorrhizae (NM) whatsoever. Compared to AM plant lineages, EM lineages tend to be less diverse but more ecologically dominant and both EM and NM plants tend to occupy drier, cooler habitats. This project addresses two outstanding questions in the evolutionary ecology of mycorrhizae in plants. First, how do plant lineages transition between mycorrhizal states and what are the ecological consequences of these transitions? Second, why are ectomycorrhizal lineages less diverse but more ecologically dominant that other plant lineages? To address these questions, we are integrating several large databases of mycorrhizal associations, functional traits and climate niches in a comparative framework using a time-calibrated megaphylogeny. The results will provide insights into the evolutionary dynamics of this important mutualistic association and its ecological consequences.