Effect of Population Density on the Demography of an Invasive Plant (Alliaria petiolata, Brassicaceae) Population in a Southeastern Ohio Forest

Abstract
As interest in invasive species management increases, new information with respect to invasive species abundance and distribution in invaded habitats is imperative. One essential type of information is demographic data. When invasive plants colonize a new habitat, their numbers may be low at first, but the population may undergo rapid expansion. We were interested in the effect of intraspecific density on the population dynamics and life history attributes of Alliaria petiolata a Eurasian biennial herb that has become an invasive pest in portions of North America. Thirty plots were established in a mesic second-growth deciduous forest in high, medium and low density patches of A. petiolata rosettes. Demographic data were collected for all A. petiolata cohorts present in the plots from 1996–1998. In June 1998 all first year rosette and second year mature individuals were harvested, dried and weighed. Stage-based population projection matrices were constructed in order to compare demography among p...