Ecological niche modeling, a new methodology for predicting the geographic course of species' invasions, was tested based on four invasive plant species (garlic mustard, sericea lespedeza, Russian olive, and hydrilla) in North America. Models of ecological niches and geographic distributions on native distributional areas (Europe and Asia) were highly statistically significant. Projections for each species to North America—effectively predictions of invasive potential—were highly coincident with areas of known invasions. Hence, in each case, the geographic invasive potential was well summarized in a predictive sense; this methodology holds promise for development of control and eradication strategies and for risk assessment for species' invasions.

Nomenclature: Hydrilla, Hydrilla verticillata (L.f.) Royle HYLLI; Russian olive, Elaeagnus angustifolia L. ELGAN; sericea lespedeza, Lespedeza cuneata (Dum.-Cours.) G. Don LESCU; garlic mustard, Alliaria petiolata (Bieb) Cavara & Grande ALAPE.