Question

Why are these species invasive?

• A. They were introduced into a foreign habitat
• B. They are weeds and will invade all habitats
• C. Their predators are extinct
• D. They grow very well in their natural habitats

Answer 1

The correct option is A They were introduced into a foreign habitat

The two plants shown here are water hyacinth and the Japanese Kudzu vine. These species co-evolve with their predators in their natural habitats. Therefore in their natural habitats, which are the Amazon basin and Japan respectively, these plants are contained by evolutionary constraints. When these species were introduced into foreign habitats, the natural constraints were absent and the species turned invasive. The water hyacinth was introduced into many countries, including India for ornamental purposes and the Japanese Kudzu was introduced into the south-eastern parts of the U.S.