2000- Assistant Professor - Research, Biological Sciences, University of New Orleans

1996-2000 Assistant Professor, Dept. Ecology, Evolution & Organismal Biology, Tulane University

1993-1995 Postdoctoral Fellow in Root Biology, Pennsylvania State University. Growth & morphology of apple roots: genetic, climatic and edaphic factors; Effects of tillage practices on mycorrhizal function in agricultural ecosystems; Roles of endo-mycorrhizal hyphae in propagation of the symbiosis. Developed and taught graduate seminar in Scientific Creativity. Funded via NSF/DOE/USDA training grant in Root Biology to H. Flores et al.

1987-1993 Research Assistant, Stanford University. Projects apart from dissertation research: Effects of harvester ant mounds on mycorrhizal associations and plant distribution in a serpentine grassland; Ecophysiology of Mexican vines, trees & cacti (several collaborative projects), Effects of elevated CO2 on California grassland ecosystems.

1988-1991 Teaching Assistant, Stanford University. Ecology and Evolutionary Biology, Ecology and Evolutionary Biology laboratory, Ecosystems of California, Plant Adaptations.

1985-1987 Technician / Research Assistant, Harvard Forest, Harvard University, with Dr. J.G. Torrey. Work included studies on 1)the ecology of nitrogen-fixing trees in New England, 2)control of the development of nitrogen-fixing actinorhizal symbioses, 3)effects of oxygen environment on the physiology of actinorhizal plants (with Dr. W.B. Silvester), and 4)attempts towards independent culture of arbuscular mycorrhizal fungi (with Dr. B. Mosse).

1984-1985 Research Assistant, Swarthmore College & Marine Biological Laboratory, Woods Hole, with Dr. M.B. Saffo. Biochemical interactions between an ascidian tunicate and its protist endosymbiont.