Research Interests

I am interested in plant population biology and conservation biology, particularly in the evolution of plant breeding systems and the population biology of invasive species. Stephen Weller (UC-Irvine) and I have used a multi-disciplinary approach to study the endemic Hawaiian genus Schiedea (Caryophyllaceae) as a model system in the evolution of plant breeding systems. This monophyletic group is undergoing a spectacular radiation in habitat and breeding system, ranging from selfing rainforest vines to dioecious subalpine herbs. Using a phylogenetic perspective, we have investigated the role that selfing, inbreeding depression, ecological factors, and allocation of resources play in the evolution of breeding systems. A major emphasis in our lab is a quantitative genetics study investigating the genetic potential for gender shifts through artificial selection experiments on two gynodioecious species, one with 13% females (the remainder hermaphroditic), and the other with 39% females. This work is in collaboration with Diane Campbell (UC-Irvine) and Theresa Culley .

A second line of research interest is in conservation biology, including examination of ecological correlates of native Hawaiian plants at risk (with Warren L. Wagner (Smithsonian Institution) ), conservation and restoration of endangered Schiedea species (with Stephen Weller), and integration of population biology concepts with the more applied needs of managers. Undergraduates and graduate students in the combined Sakai-Weller lab have worked on research in both plant breeding systems and the population biology of invasive species.

Degrees

Honors and Awards

Current Graduate Students

Jessica Poulin

Recent Graduates of the Lab

Current Post-docs

Recent Courses Taught

Ecology (Bio 96)
Plant population biology (Bio 167)
Field methods in ecology (Bio 166)
Undergraduate research (Bio 199)
Writing proposals, graduate level (EE 204)
Evolution, graduate level (EE 206)
Plant ecology graduate seminar (EE 221)
Graduate research (Bio 200)

Links

Recent Papers

Rankin, A. E., S. G. Weller, and A. K. Sakai. 2002. Mating system instability in Schiedea menziesii (Caryophyllaceae). Evolution 56: 1574-1585.

Culley, T. M., S. G. Weller, and A. K. Sakai. 2002. The evolution of wind pollination in angiosperms. Trends in Ecology and Evolution: 17: 361-369 + corrigendum

Sakai , A. K., W. L. Wagner, and L. Mehrhoff. 2002. Patterns of endangerment in the Hawaiian flora. Systematic Biology 51: 276-302.

Sakai , A. K. and D. F. Westneat. 2001. Mating systems. in C. W. Fox, D. A. Roff, and D. J. Fairbairn, eds. Evolutionary Ecology: Concepts and Case Studies. Oxford University Press. pp. 193-206.

Sakai , A. K., F. W. Allendorf, J. S. Holt, D. M. Lodge, J. Molofsky, K. A. With, S. Baughman+, R. J. Cabin, J. E. Cohen, N. C. Ellstrand, D. E. McCauley, P. O'Neil, I. M. Parker, J. N. Thompson, and S. G. Weller. 2001. The Population Biology of Invasive Species. Annual Review of Ecology and Systematics. 32: 305-33

Cabin, R. J., S. G. Weller, D. H. Lorence, T. W. Flynn, A. K. Sakai, D. Sandquist, and L. J. Hadway. 1999. Preservation and restoration of a Hawaiian tropical dry forest: the effects of long-term ungulate exclusion and recent alien species control. Conservation Biology. 14:439-453.

Weller, S. G. and A. K. Sakai. 1999. Using phylogenetic approaches for the analysis of plant breeding system evolution. Annual Reviews of Ecology and Systematics. 30: 167-199.