Date of this Version
Biological invasions assisted by humans are impoverishing biological diversity worldwide (MacDonald et al. 1989, Diamond 1989). Such invasions are particularly devestating to the biota of oceanic islands such as Hawaii (Williamson 1981, Brockie et al. 1988, Hawaii Department of Land and Natural Resources et al. 1991). Ecosystems of the Hawaiian Islands are much more vulnerable to biological invasions than are continental ecosystems, because the organisms in them have evolved in isolation from many of the forces that have shaped continental organisms, including foraging and trampling by herbivorous mammals, predation by ants and mammals, virulent diseases, and fires (Loope & Mueller-Dombois 1989). Lowland ecosystems of the Hawaiian Islands were substantially modified by Polynesians prior to western contact (Kirch 1982); after Cook's 'discovery' of the islands in 1778, the rate of modification accelerated and extended to higher elevations (Cuddihy & Stone 1990).