Invasive alien species are a global problem, with countries having to invest heavily to avoid species from other countries impacting negatively on their local ecosystems. These species are introduced primarily by humans; sometimes accidentally, while at other times very much intentionally.
Many of the organisms introduced to areas outside their natural range are beneficial, or have little or no benefit, but there are some species that we have to be concerned about – those plant and animal species that dramatically increase their numbers in the environmental and climatic region they now share with us. With no natural enemies, invasive species have a competitive advantage over indigenous species, as they are able to reproduce rapidly to spread and invade local ecosystems. They degrade the ecosystems they invade and impact negatively on our environment, economy and even our health. Alien plant species may exacerbate flooding and increase the risk of runaway fires, reduce our natural water resources, impact on the natural functioning of ecosystems and inhibit growth of indigenous vegetation. As required by law, they must be removed.