Summary: 511
Ecological Monographs, 71(4), 2001, pp. 511­530
2001 by the Ecological Society of America
SONORAN DESERT COLUMNAR CACTI AND THE EVOLUTION OF
GENERALIZED POLLINATION SYSTEMS
THEODORE H. FLEMING,1
CATHERINE T. SAHLEY,2
J. NATHANIEL HOLLAND,1
JOHN D. NASON,3
AND
J. L. HAMRICK4
1
Department of Biology, University of Miami, Coral Gables, Florida 33124 USA
2CONATURA, Apartado 688, Arequipa, Peru
3Department of Botany, Iowa State University, Ames, Iowa 50011 USA
4Departments of Botany and Genetics, University of Georgia, Athens, Georgia 30602 USA
Abstract. We studied variation in flowering phenology, fruit and seed set, and the abundance of the pol-
linators of four species of night-blooming Sonoran Desert columnar cacti for up to eight years at one site in
Mexico and one year at one site in Arizona. We determined how spatiotemporal variation in plant­pollinator
interactions affects the evolution of generalized pollination systems. We conducted pollinator exclusion and

Source: Azevedo, Ricardo - Department of Biology and Biochemistry, University of Houston
Holland, J. Nathaniel - Department of Ecology and Evolutionary Biology, Rice University

Collections: Biology and Medicine; Environmental Sciences and Ecology