Nonindigenous species affect native ecosystems, communities, and populations in myriad ways, from plants (and a few animals) that overgrow entire communities, to plants and animals that hybridize individual native species to a sort of genetic extinction. Further, nonindigenous species sometimes interact to worsen each others impact. These impacts are commonly seen in national parks throughout the United States. The key policy change required to alleviate this threat is a shift from blacklists of prohibited species and a presumption of harmlessness to combinations of white and blacklists and a presumption that any species may be damaging. This new guiding philosophy must be inculcated at international and national levels, which will not be easy during a period when free trade is seen as an unmitigated blessing. Within the United States, enhanced cooperation and coordination will be required among all parties (i.e., federal, state, and local agencies as well as private entities) charged with managing invasions. Internationally, the key forum is the World Trade Organization. Various management tools available to combat nonindigenous species have produced some striking successes, but new research could improve their effectiveness and reliability. There is a particular need for research on ecosystem management to control introduced species. In the face of the increasingly publicized onslaught of invaders, there is a widespread tendency to view increased biotic homogenization as inevitable. However, advances in both policy and technology could greatly slow this process and perhaps (in concert with restoration measures) even reverse it. The necessary pressure and resources to effect these changes must come from an increasingly alarmed and vocal public.
"Biological invasions—How are they affecting us, and what can we do about them?,"
Western North American Naturalist: Vol. 61
, Article 7.
Available at: http://scholarsarchive.byu.edu/wnan/vol61/iss3/7