Deliberate Introductions of Species: Research Needs

The silent invasion of Hawaii by insects, disease organisms, snakes, weeds and other pests is the single greatest threat to Hawaii's economy and natural environment.... Even one new pest-like the brown tree snake-could forever change the character of our islands. (Coordinating Group on Alien Pest Species 1996, p. 1) Reforestation in the tropics is so vastly behind deforestation that we cannot wait to fully appraise all the potential negative elements of domestication. Weediness is of consequence perhaps in Honolulu, but not inAddis or Delhi. (James Brewbaker, quoted by Hughes 1994, p. 244) ntroductions of nonindigenous organisms can be both a boon and a bane to society. Humans depend heavily on non-native organ-isms for food, shelter, medicine, ecosystem services, aesthetic enjoyment, and cultural identity. Over 70% of the world's food comes from just nine crops (wheat, maize, rice, po-tato, barley, cassava, soybean, sugar cane, and oats; Sattaur 1989, Prescott-Allen and Prescott-Allen 1990), each of which is cultivated far beyond its natural range. Similarly, 85% of industrial forestry plantations are established with species of just three genera (Eucalyptus, Pinus, and Tectona), which are also largely cultivated as exotics (Evans 1992). Thus, although native organisms fulfill some human requirements, nonnative organisms play an integral role in the economies and cultures of all regions (Figure In New Zealand, for example, more than 95% of export earnings derives from alien species (New Zealand Department of Statistics 1996).