Cycads are among the most vulnerable and threatened plant groups worldwide. They evolved ~280 million years ago and became widespread during the Jurassic, but their abundance dramatically declined during the mass extinction that led to the demise of the dinosaurs at the end of the Cretaceous.

Project Title: Mechanisms of persistence and coexistence of a rare ancient cycad

We are specifically interested in the possible mechanisms that explain the persistence and coexistence of the rare cycad Dioon sonorense within an angiosperm-dominated world. In this context, we are studying: a) the effects of the environment and demography on the persistence of D. sonorense, b) mechanisms of coexistence such as facilitation by or competition from modern plant species, and c) differences in water-use efficiency and nitrogen sources (atmospheric N2 vs. soil N) between D. sonorense and co-occurring species.

Location: State of Sonora, northwestern Mexico

Timeline: 2008-2012

Field participants:
SUNY-ESF: Juan C. Álvarez-Yépiz
Instituto Tecnológico de Sonora: Alejandro Cueva, Enrico Yépez
Sierra de Alamos-Rio Cuchujaqui Biosphere Reserve: Elvira Rojero, Alma Montaño
Instituto de Ecología, UNAM: Alberto Búrquez, Angelina Martínez-Yrízar

Principal Investigators:
Juan C. Álvarez-Yépiz, Martin Dovčiak, SUNY College of Environmental Science and Forestry

Fulbright-García Robles Fellowship (COMEXUS),
PLACA Summer Research Grant (Syracuse University),
Instituto de Ecología, UNAM

For more information visit: and

Juan C. Álvarez-Yépiz, SUNY College of Environmental Science & Forestry, 452 Illick Hall, 1 Forestry Drive, Syracuse, NY 13210, Email:, Phone: (315) 470-6802