ABSTRACT
Invasion by exotic species is a significant problem, reaching epidemic proportions and costing the American public an estimated US$137 billion or about US$1300 per household each year as determined by loss of productivity, costs of herbicides, and other measures (Pimentel et al. 2000). The health and longevity of many forest ecosystems are also at risk because of significant invasion by exotic plants, resulting in loss of native species, deterioration of natural regenerative processes, decreases in forest productivity, and degradation of the environment. Moreover, the effects of invasion by exotic species have proved to be long lasting and cumulative (Chornesky et al. 2005).
