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Bio Words
nonnative (exotic, alien, introduced, or non-indigenous) species: any species, including its seeds, eggs, spores, or other biological material capable of propagating that species, that is not native to that ecosystem
invasive species: a nonnative species whose introduction does or is likely to cause economic or environmental harm or harm to human health |
Purple loosestrife can produce up to 2.7 million seeds per plant yearly and
spreads across approximately one million additional acres of wetlands each year.
Scientists have found that usually only one species survives in laboratory experiments studying this type of interaction. However, the real world is a much more complex situation. At times two competitive species can exist together. For example, both hawks and owls hunt mice. Hawks hunt by day and owls hunt by night.
Introducing Nonnative Species
Sometimes a new species that has not been there before is introduced into an ecosystem. This is called a nonnative species. (Other terms that you may hear used to refer to these organisms are exotic, alien, introduced, or non-indigenous.) The introduction can be either intentional or accidental. Introduction of a nonnative species can have negative effects on the ecosystem. When this happens the species is considered invasive. It can cause economic or environmental harm, or harm to human health. Invasive species can be plants, animals, and other organisms (e.g., microbes). All these terms are clearly defined by the U.S. government (Executive Order 13112).
Why is the government so concerned with invasive species? Why should the public be concerned?
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