We know so little about how these systems function, what these systems comprise, and how species interact within them. More basic research on the content of ecosystems and how they function is clearly needed. Scientists have begun to identify common characteristics of invasive species. Invasives tend to have high population growth rates, produce large quantities of fruit or offspring, be able to disperse over distances, mature rapidly, utilize generalized pollinators, and lack the diseases, predators, or herbivores that controlled them in their native environment. Habitat disruption, in the form of soil disturbance, landscape fragmentation, changes in water regimes, and changes in nutrient content of soil or water, enhances the capabilities of most invasive species to spread.
Some species become invasive within a decade of their introduction, others can take centuries.
Researchers are developing models to predict the potential invasiveness of introduced species, but such models will be intellectual exercises only if they are not used to make decisions about the plant and animal species that are deliberately brought into new areas. The flow of invasive species will never stop, but perhaps it can be slowed down. Early detection and eradication programs are crucial, as is the refinement of control techniques, especially those that minimize the quantity of pesticides used and the disturbance of habitats. Public education is critical. This serious issue affects health, water supplies, fisheries, agriculture, recreation, property values, ecosystem function, and how tax dollars are spent.