Abstract
Oaks (Quercus, Fagaceae) are the dominant tree genus of North America in species number and biomass, and Mexico is a global center of oak diversity. Understanding the origins of oak diversity is key to understanding biodiversity of northern temperate forests. A phylogenetic study of biogeography, niche evolution and diversification patterns in Quercus was performed using 300 samples, 146 species. Next-generation sequencing data were generated using the restriction-site associated DNA (RAD-seq) method. A time-calibrated maximum likelihood phylogeny was inferred and analyzed with bioclimatic, soils, and leaf habit data to reconstruct the biogeographic and evolutionary history of the American oaks. Our highly resolved phylogeny demonstrates sympatric parallel diversification in climatic niche, leaf habit, and diversification rates. The two major American oak clades arose in what is now the boreal zone and radiated, in parallel, from eastern North America into Mexico and Central America. Oaks adapted rapidly to niche transitions. The Mexican oaks are particularly numerous, not because Mexico is a center of origin, but because of high rates of lineage diversification associated with high rates of evolution along moisture gradients and between the evergreen and deciduous leaf habits. Sympatric parallel diversification in the oaks has shaped the diversity of North American forests.
Original language | English (US) |
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Pages (from-to) | 439-452 |
Number of pages | 14 |
Journal | New Phytologist |
Volume | 217 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2018 |
Bibliographical note
Funding Information:Assistance in the laboratory and field was provided by staff at Floragenex; Breane Budaitis; students, postdocs and interns in the Hipp, González-Rodríguez, Manos and Cavender-Bares laboratories; Bethany Brown; Guy Sternberg and staff of Starhill Forest Arboretum; Ian Pearse, Jill Baty, Emily Griswold and staff of UC-Davis Shields Oak Grove; Beth Fallon; Jeanne Romero-Severson; and staff at the Southwestern Research Station. Discussions and feedback on initial drafts of the manuscript were provided by Deren Eaton, Emily Sessa, M. Socorro González Elizondo, Hernando Rodríguez-Correa, the Systematics Lab of The Morton Arboretum, and three anonymous reviewers. Funding for this project was provided by NSF Awards 1146488, 1146102 and 1146380, a Fulbright-Comexus grant to J.C-B. and The Morton Arboretum Center for Tree Science.
Publisher Copyright:
© 2017 The Authors. New Phytologist © 2017 New Phytologist Trust
Keywords
- American oaks
- Quercus
- convergence
- niche evolution
- phylogeny
- restriction site-associated DNA sequencing (RAD-seq)
- sympatric parallel diversification
- woody plants