By Environmental Management System
Exotic invasives are everywhere and North Carolina is no exception. A study by Pimentel, D., R. Zuniga, and D. Morrison in 2004 estimated that there are approximately 50,000 exotics/aliens in the U.S. Corn, L.C. et al (1999) calculated that there were 4,300 exotic invasives. These numbers are probably low since they reflect the numbers from a decade ago.
Where did the exotics come from and how? There are many sources and origins with the majority linked to - Africa, Asia, China, Europe, India, South America, Australia, and even between regions within the U.S. These temperate continents have certainly provided their share of species and most likely will continue to do so. Through the centuries, species have entered the U.S. by various routes, sometimes being introduced intentionally, other times unintentionally. Here are some of the ways species have entered and spread.
We rely on Environmental Biologists, Ecologists and organizations like the North Carolina Native Species Society, North Carolina Botanical Garden, Mid-Atlantic Exotic Pest Plant Council, USDA SRS, and National Park Service, to mention only a few, to provide education and help to designate organisms that have become or might become problematic.
Because invasives are defined by the ecosystem being evaluated, what may be considered a threat one place may not have the same impact in another. Once again the 4Ws (who, what, when, and where) influence what may be included on the lists of species. Certainly the exotic must easily adapt, be prolific with few controls, and disturb biodiversity and biosystems.
We have provided some examples of the most notorious invasive plants, animals, and microbes (pathogens). Some you’ll know but maybe some will surprise you. Presented now are some organisms that require watching closely.
Corn, L.C., E.H. Buck, J. Rawson, and E. Fischer. 1999. Harmful Non-Native Species: Issues for Congress. Congressional Research Service Issue Brief, RL30123.
Pimentel, D., R. Zuniga, and D. Morrison. 2004. Update on the environmental and economic costs associated with alien-invasive species in the United States. Ecological Economics Volume 52, Issue 3, 15 February 2005, Pages 273-288