| Roger Graveson's
The Plants of Saint Lucia: Invasive
Species |
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A
naturalized species is an introduced alien (non-native) species that
spreads into the wild and whose reproduction in the wild is sufficient
to maintain or increase its population.
An invasive species is a naturalized species that causes or is likely to cause economic or ecological/environmental harm or harm to human health. (Some indigenous species also have the same effect in disturbed areas and under some definitions are considered invasive as well). Because it is impossible to determine whether species arrived naturally or were introduced by Amerindians, I define an introduced alien as any species which has arrived in Saint Lucia from the colonial period onwards. Most of our naturalized species are found in areas which have been altered by human activities such as cultivation, animal husbandry, charcoaling, clearing for settlements and modification of drainage pattern. The rain forest reserve and the Pitons remain relatively free of naturalized species. Some naturalized species are very common but not invasive - they seem to cause no harm. Many of our most common grasses are naturalized and are found in altered habitats such as cleared/burnt forest, farms and roadsides. The species listed on this page are included because they are: a) invasive in Saint Lucia b) potentially invasive in Saint Lucia c) included on the "100 of the World's Worst Invasive Alien Species" list. |
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