North American tree migration paced by climate in the West, lagging in the East

Tree fecundity and recruitment have not yet been quantified at scales needed to anticipate biogeographic shifts in response to climate change. By separating their responses, this study shows coherence across species and communities, offering the strongest support to date that migration is in progress with regional limitations on rates. The southeastern continent emerges as a fecundity hotspot, but it is situated south of population centers where high seed production could contribute to poleward population spread. By contrast, seedling success is highest in the West and North, serving to partially offset limited seed production near poleward frontiers. The evidence of fecundity and recruitment control on tree migration can inform conservation planning for the expected long-term disequilibrium between climate and forest distribution.

Shubhi Sharma, Robert Andrus, Yves Bergeron, Michal Bogdziewicz, Don C. Bragg, Dale Brockway, Natalie L. Cleavitt, Benoit Courbaud, Adrian J. Das, Michael Dietze, Timothy J. Fahey, Jerry F. Franklin, Gregory S. Gilbert, Cathryn H. Greenberg, Qinfeng Guo, Janneke Hille Ris Lambers, Ines Ibanez, Jill F. Johnstone, Christopher L. Kilner, Johannes M. H. Knops, Walter D. Koenig, Georges Kunstler, Jalene M. LaMontagne, Diana Macias, Emily Moran, Jonathan A. Myers, Robert Parmenter, Ian S. Pearse, Renata Poulton-Kamakura, Miranda D. Redmond, Chantal D. Reid, Kyle C. Rodman, C. Lane Scher, William H. Schlesinger, Michael A. Steele, Nathan L. Stephenson, Jennifer J. Swenson, Margaret Swift, Thomas T. Veblen, Amy V. Whipple, Thomas G. Whitham, Andreas P. Wion, Christopher W. Woodall, Roman Zlotin, & James S. Clark
Proceedings of the National Academy of Sciences