Quantitative Methods for Assessing NIS Populations for Invasiveness

Plant species, as a taxonomic group can not be judged to be invasive. However, there are some plant species that have traits that allow a subset of their populations to be invasive. That is, there will always be variation in invasiveness of a plant species across the environments where it has become established regardless of its notoriety as an invasive species. In fact, there may be many environments where populations of notoriously invasive species are not at all invasive and may be going locally extinct following a rare establishment event. The main point is that the focus for determination of invasiveness for management considerations should be placed on populations or meta-populations segregated by environments rather than on species across their entire range of distribution.