Grantee Research Project Results
Population Structure and Process in a Woody Bamboo: Genet-Based Life Table Response Experiments in Arundinaria gigantean (Fam. Poaceace, Tribe Bambusoideae)EPA Grant Number: U916181
Title: Population Structure and Process in a Woody Bamboo: Genet-Based Life Table Response Experiments in Arundinaria gigantean (Fam. Poaceace, Tribe Bambusoideae)
Investigators: Gagnon, Paul R.
Institution: Louisiana State University - Baton Rouge
EPA Project Officer: Graham, Karen
Project Period: January 1, 2003 through January 1, 2006
Project Amount: $107,579
RFA: STAR Graduate Fellowships (2003)
Research Category: Academic Fellowships , Fellowship - Terrestrial Ecology and Ecosystems , Ecological Indicators/Assessment/Restoration
The objective of this research project is to illuminate the biology of guerilla clonal plants by focusing on canebrake ecology. Molecular markers such as microsatellites now make it possible to genotype plant (ramets) to individual genets and, thereby, explore new dimensions in underlying population and genetic structures (Hoelzel, 1998). A capacity for vigorous clonal growth is a common feature among persistent plant colonizers (Connell and Slatyer, 1977; Sackville Hamilton, et al., 1987). Guerrilla clonal plants can spread sizeable distances horizontally—under favorable conditions they can rapidly colonize new space and resources (Lovett-Doust and Lovett-Doust, 1982; Sackville Hamilton, et al., 1987). Studies of guerilla plants are hindered by practical difficulties distinguishing genetic individuals (genets) with interdigitating clonal shoots (ramets) (Silvertown and Lovett-Doust, 1993).
Canebrakes were dense riverine thickets formed by America's only native bamboo. This widespread and immensely productive ecosystem harbored diverse wildlife (Judziewicz, et al., 1999) and offered European settlers some of North America's most nutritious forage (Hughes 1966) and richest agricultural land (Platt and Brantley, 1997). Today, the canebrake ecosystem has virtually disappeared, and certain associated wildlife, including Carolina parakeets and Bachman's warblers, are extinct (Remsen, 1986; Judziewicz, et al., 1999). Paradoxically, cane persists throughout much of its previous range, but it no longer attains the density or stature of the canebrakes encountered by early explorers (Marsh, 1977; Platt and Brantley, 1997).Approach:
By combining the analysis of molecular markers with data from experimental field plots, I will conduct life table response experiments on cane (see Caswell, 2001). Results will provide key insights into the competitive processes of guerilla bamboos, with implication for other fast-growing plant colonizers. Canebrake restoration efforts also will benefit from results of this study.
I hypothesize that: (1) canebrakes were comprised of a few genetically unique overlapping genets, so that multiple genets might co-occur at a single site; (2) the infrequency of Arundinaria flowering events will manifest in low local genetic diversity within few genetic individuals; (3) major disturbances such as windstorms and natural lightning season fires promote the growth and expansion of Arundinaria genets versus competing species of hardwood trees and shrubs; and (4) without the opening provided by such disturbances, Arundinaria genets are unable to attain the tall stature and high culm density that characterizes canebrakes.Supplemental Keywords:
fellowship, bamboo, guerilla bamboo, Arundinaria gigantean, canebrakes, canebrake ecology, plant colonal shoots, ramets.