This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.
This award will support a twenty-four-month research fellowship by Dr. Brooke S. Baythavong to work with Dr. Ernesto Gianoli at Universidad de Concepcion in Chile.
Invasive species undergoing rapid range expansions experience a variety of novel environments. Successful establishment in a novel range is likely to be facilitated by some combination of genetic variation among lineages within a population and phenotypic plasticity. This research is focused on understanding the relative importance of quantitative genetic variation and phenotypic plasticity in determining the relative success of populations of an invasive annual plant species, Erodium cicutarium, undergoing a recent range expansion in California and Chile. The project utilizes field surveys, greenhouse experiments, and Bayesian modeling techniques to address several questions including: 1) How does trait expression respond via phenotypic plasticity to environmental variation?, 2) Do genotypes from habitats with greater environmental heterogeneity express greater plasticity than genotypes from relatively homogeneous environments?, and 3) Do the roles of genetic and plastic variation in trait values in determining the relative success of a population differ between invasion fronts in Chile and California? The PI will provide novel insight into the role of phenotypic plasticity and quantitative genetic variation in determining the relative success of populations in the process of rapid range expansion in replicate invasion fronts. Although the spatial scale of environmental heterogeneity has long been hypothesized to play an important role in determining patterns of selection on the expression of phenotypic plasticity no comprehensive tests exist. Previous studies examining the importance of genetic variation or phenotypic plasticity in the range expansions of invasive species have lacked comprehensive analyses of plasticity in response to environmental variation similar to that experienced in natural habitats. This research provides the first comprehensive analysis to date.
Invasive species pose a serious threat worldwide both to local and national economies, and to the integrity of ecosystems and native species diversity. Over the past 250 years, most of California?s grasslands have become dominated by invasive Eurasian annual plants, including the annual forb E. cicutarium. Although invasive Eurasian forbs also pose a threat to native ecosystems in Chilean grasslands, invasive plant community composition and interspecific interactions differ significantly between Chile and California. Because this research incorporates lineages collected across replicate invasion fronts it provides a novel comparison between populations collected in two geographically distant range edges of the same plant species.
