Georgia Invasive Species Task Force

What is an invasive species? An invasive species is any species (including its seeds, eggs, spores, or other biological material capable of propagation) that is not native to a given ecosystem; and whose presence causes economic or environmental harm or harm to human health. Some of the invasive species on this web site are already serious pests in Georgia while some are currently just threats and not yet widespread.

How do invasive species get here? Invasive species are introduced into a new environment, either intentionally or accidentally. Intentional introductions have often been for agricultural or ornamental purposes. Once introduced, they escape from cultivation, or from their aquariums or cages in the case of animals, and become established as viable, self-reproducing populations. Accidental introductions are usually the result of contaminated freight, where individuals or the seeds from invasive species are mixed within normal freight.

Are all exotic species invasive? No, actually only a small percent of the introduced species ever become invasive. However, it is nearly impossible to predict which species will become invasive and new species are being introduced every day. Some species have been introduced for many years before becoming invasive. These are thought to go through a “lag phase” in which their populations grow slowly until they reach a size large enough for the population to explode and become invasive. Chinese privet is a good example of this in the Southeast. Chinese privet has been in the Southeast for many years but until recently its population remained at low numbers. Now it is a serious invasive species, found throughout nearly all of the Southeast.

What type of harm do invasive species cause? Since invasive species are in a new environment, free from the natural predators, parasites, or competitors of their native habitats, they often have very high population sizes. These large populations can out-compete and displace native species, or can reduce wildlife food and habitat. Some also have the potential to disrupt vital ecosystem functions, such as water flow, nutrient cycling, or soil decomposition. Other invasive species cause massive amounts of economic damage to the agricultural industry. They can harm or kill crops, clog equipment, or contaminate produce. Some invasive species can cause direct harm to humans or domestic animals.