The distribution and abundance of populations.

The first step to understanding an invasive species is to learn about its distribution and abundance. In this view, this chapter discusses measures to learn about the distribution and abundance of invasive species. It is established that to better understand a species, the following questions about distribution must be addressed: whether the species are at its current limit of distribution; if the species continue to expand into new locations; whether the species are found on specific soil types or land forms; and whether there are likely dispersal routes for this species. Further, information can also be gained on species' characteristics, such as dispersal mechanisms or habitat preferences, by looking at distribution changes.