Invasive species

An invasive species, also called an invasive exotic, is an organism that is intentionally or accidentally introduced to an area where it is not native, and where it successfully invades and disturbs natural ecosystems, displacing native species[?]. The term is most often applied to plants.

Invasive Exotic Plants Many invasive plants have been introduced into the United States and Australia as either ornamentals or erosion controls.

Some of the most serious invasive exotics are vines, such as kudzu.

Some of the most damaging invasive exotics in the eastern United States are listed below:

• Lonicera japonica -- Japanese honeysuckle[?]
• Lonicera maackii -- Amur honeysuckle[?]
• Rosa multiflora -- multiflora rose[?]
• Lythrum salicaria -- purple loosestrife[?]
• Pueraria montana -- kudzu (aka Pueraria lobata)
• Celastrus orbiculatus -- oriental bittersweet[?]
• Elaeagnus umbellata -- autumn-olive[?]
• Alliaria petiolata -- garlic-mustard[?]

A major invasive species in Europe is Caulerpa taxifolia[?], a Mediterranean clone weed, also called Killer algae.

C. taxifolia was observed for the first time in the Mediterraneen sea in 1984, along the coast of Monaco. In 1997, it already covered around 5000 hectares. It has a strong potential to overgrow natural biotopes, and represent a major risk for the sublittoral ecosystems. Hypothesis of the origin of the algua are either a migration from the Red Sea, or introduction from a aquarium.

Invasive Exotic Animals One of the most egregious examples of introducing an invasive exotic animal was perpetrated by one Eugene Scheiffer, a Shakespeare fan, who deliberately released eighty starlings into Central Park in New York City in 1890, and another forty in 1891. He did so because he wanted to introduce all of the birds mentioned in Shakespeare's plays into the United States! Ironically, the starling had been introduced previously into Ohio and had failed to survive.

A number of invasive exotics in Australia are listed below:

• rabbit
• Brown hare[?]
• European red fox[?]
• common starling
• nutmeg mannikin[?]
• cane toad
• brown trout[?]
• mosquitofish[?]
• honeybee

Other outstanding examples of invasive exotic animals include the gypsy moth in eastern North America, zebra mussel[?] and alewife[?] in the Great Lakes and the possum in New Zealand.

Invasive Exotic Diseases History is rife with the spread of invasive exotic diseases, such as the introduction of smallpox into the Americas, where it obliterated entire Native American civilizations before they were ever even seen by the Europeans.

Invasive exotic disease introductions in the past century or so include the chestnut blight which has virtually extinguished the American chestnut, and Dutch elm disease, which has severely damaged the American elm.

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The term "invasive exotic" is generally not used for economically valuable crops and livestock, although they can have larger effects on ecosystems than even the most successful weeds.

See also

• Rabbit invasion in Australia
• Biodiversity