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Research
My current research is in three principal areas: the reproductive biology of flowering plants, the flora and natural history of central Massachusetts, and the ecology of invasive species.
My interests in reproductive biology lie in understanding the ecological function and adaptive basis of reproductive traits. My current work is an attempt to understand the functional significance of having two different sexual types of flowers on a plant. Asters and goldenrods, for example, bear both female and bisexual flowers. Students and I investigated the possibility that the presence of these two flower types permits plants to be flexible in their allocation of resources to male and female functions. We found little evidence to support this hypothesis in either plant group. I am currently examining similar issues in sedges, a group of wind-pollinated plants that bear male and female flowers.
My floristic work has involved the compilation of a flora of Worcester, Massachusetts. Field work for this project revealed several dozen species not previously recorded in the county and several records of native species rare in Massachusetts. These findings illustrate the poor state of documentation of our biological surroundings. I am expanding this work to the county level, and have conducted floristic surveys at several other Massachusetts sites. This work has several goals. One is to understand the ranges and ecological affinities of our native flora. A second, using comparisons with herbarium records, is to understand what species are most susceptible to habitat changes wrought by humans.
Invasive and Native Species: My floristic work has revealed a great abundance and diversity of introduced species. These comprise roughly a third of the plant species in central Massachusetts. Of particular concern among these are species that thrive in natural communities. These species can alter the ecology of these communities and sometimes pose a threat to rare native species. Together with several students I have been examining the abundance and distribution of introduced tree species in urban woodlands, with special emphasis on Norway maple. This shade-tolerant tree is commonly used for street and garden plantings and appears able to outcompete native species in some natural woodlands.
Recent Publications
Bertin, R. I. 2007. Sex allocation in Carex (Cyperaceae): effects of light, water and nutrients. Canadian Journal of Botany, in press.
Bertin, R. I., B. G. DeGasperis and J. M. Sabloff. 2006. Land use and forest history in an urban sanctuary in central Massachusetts. Rhodora 108: 119-141.
Bertin, R. I., M. E. Manner, B. F. Larrow, T. W. Cantwell and E. M. Berstene. 2005. Norway maple (Acer platanoides) and other non-native trees in urban woodlands of central Massachusetts. Journal of the Torrey Botanical Society, 132:225-235
Routley, M. B., R. I. Bertin and B. C. Husband. 2004. Correlated evolution of dichogamy and self-incompatibility: a phylogenetic perspective. International Journal of Plant Science 165:983-993.
Bertin, R.I. 2002. Losses of native plant species from Worcester, Massachusetts. Rhodora 104:325-349.
Bertin, R.I. and G. M. Gwisc. 2002. Floral sex ratios and gynomonoecy in Solidago (Asteraceae). Biological Journal of the Linnean Society 77:413-422.
Bertin, R. I., K. B. Searcy and P. Somers. 2002. A new native plant for Massachusetts, Carex backii (Cyperaceae). Rhodora 104:201-204.
Bertin, R. I. 2001. Life cycle, demography, and reproductive biology of herb Robert (Geranium robertianum). Rhodora 103:96-116.
Bertin, R. I. 2000. Vascular flora of Worcester, Massachusetts. New England Botanical Club.
You may download the supplement to this monograph by pressing here.
Bertin, R. I. and M. A. Kerwin. 1998. Floral sex ratios and gynomonoecy in Aster (Asteraceae). American Journal of Botany 85:235-244.
Sage, T.L., R.I. Bertin, and E.G. Williams. 1994. Ovarian and other late-acting self-incompatibility systems. In E.G. Williams, A.E. Clarke, R. B. Knox (eds.) Genetic control of self-incompatibility and reproductive development in flowering plants. Pgs. 116-140. Kluwer Academic Publishers, Dordrecht.
Bertin, R.I. and C.M. Newman. 1993. Dichogamy in angiosperms. Botanical Review 59:112-152.
Bertin, R.I. 1993. Incidence of monoecy and dichogamy in relation to self-fertilization in angiosperms. American Journal of Botany 80:537-560.
Bertin, R.I., and O.D.V. Sholes. 1993. Weather, pollination and the phenology of Geranium maculatum. American Midland Naturalist 129:52-66.
Bertin, R.I., and P.J. Peters. 1992. Paternal effects on offspring quality in Campsis radicans. American Naturalist 140:166-178.
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