Plants which have been translocated by human agency into lands or waters where they have not lived previously, at least during historic times. Such translocation of species always involves an element of risk if not of serious danger. Newly arrived species may be highly competitive with or otherwise adversely affect native species and communities. Some may become a nuisance through sheer overabundance. They may become liable to rapid genetic changes in their new environment. Many harmful introductions have been made by persons unqualified to anticipate the often complex ecological interaction which may ensue. On the other hand many plants introduced into modified or degraded environments may be more useful than native species in controlling erosion or in performing other positive functions.
Scope note is not available.