The Genet and Ramet Population Dynamics of Solidago Canadensis in an Abandoned Field

Abstract

SUMMARY (1) Populations of Solidago canadensis were studied on an abandoned agricultural field in east-central Illinois. The patterns of genet recruitment, the population dynamics of genets and ramets following colonization, and changes in genet diversity during succession were examined. (2) Invasion occurred mainly during the third, fourth and fifth years after the field was abandoned. There was no recruitment after the sixth year, but rapid clonal expansion of the established genets caused ramet densities to continue to increase for several years. (3) Both genet survivorship and clonal growth were inversely related to the time of recruitment, so that after a few years the populations were composed mainly of genets that had established during the first year of colonization. (4) The density of genets reached a maximum in the fifth year and then slowly declined. The density and composition of genets in an adjacent 15-year old field remained constant over 6 years suggesting that the number of genets may reach an equilibrium in older populations and a diversity of genets may be maintained. (5) The interdependence among ramets within clones and their ability to integrate environmental heterogeneity may buffer against localized 'patch-specific' selective influences resulting in little differential mortality among genotypes. This may be one mechanism maintaining a diversity of genets in successional S. canadensis populations.