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Invasive species


Invasive species” or “alien species” defined by the EU (2017:7) as “animals and plants that have been introduced through human action to a new natural environment from other parts of the world […]. [T]he new natural environment turns out to be surprisingly favorable, in particular in the absence of their natural enemies. This allows them to spread and reproduce excessively, feeding on native species or out-competing them for habitat and resources; sometimes also carrying parasites and diseases that are lethal to native wildlife or dangerous to human health.


Impacts of invasive species


Invasive species or invasive alien species (IAS) establish and spread in non-native ecosystems and outcompete or prey upon resident species (Horan et al. 2002). The spread of species in non-native ecosystems started in the age of exploration where humans crossed the ocean for trading and colonialization, where they either accidentally or intendedly carried plants and animals with them: Some animals or plants traveled accidentally as ballast water in ships while others were introduced for decoration, hunting or cultivation purposes (Mooney & Cleland 2001).

The animals presented in the figure above are according to the Smithsonian Institute (2010) some of the worst invasive mammals known. They were introduced accidentally (raccoon, grey squirrel) or willingly for food supply or hunting purposes (rabbit, red deer). Mostly, it is even unknown to people that these animals were not naturally part of the ecosystem they are found in nowadays (Smithsonian Institute 2010; ISSG).


A non-native species once established could become an invader and a threat to the native environment. In the worst case they have the potential to alter the ecosystem and create a monoculture (Eisenwerth & Johnson 2002). They could be seen as some kind of evil-minded tourist that seems harmless but causes trouble for native environments.


References and further reading

  • Blackburn, T. M., Pyšek, P., Bacher, S., Carlton, J. T., Duncan, R. P., Jarošík, V., Wilson,J. & Richardson, D. M. (2011). A proposed unified framework for biological invasions. Trends in ecology & evolution, 26(7), 333-339.

  • Caut, S., Angulo, E., & Courchamp, F. (2009). Avoiding surprise effects on Surprise Island: alien species control in a multitrophic level perspective. Biological Invasions, 11(7), 1689-1703.

  • Devin, S., & Beisel, J. N. (2007). Biological and ecological characteristics of invasive species: a gammarid study. Biological Invasions, 9(1), 13-24.

  • Dukes, J. S., & Mooney, H. A. (1999). Does global change increase the success of biological invaders?. Trends in Ecology & Evolution, 14(4), 135-139.

  • Eiswerth, M. E., & Johnson, W. S. (2002). Managing nonindigenous invasive species: insights from dynamic analysis. Environmental and resource economics, 23(3), 319-342.

  • Elliott, M. (2003). Biological pollutants and biological pollution––an increasing cause for concern. Marine Pollution Bulletin, 46(3), 275-280.

  • Eskridge, A. E., & Alderman, D. H. (2010). Alien invaders, plant thugs, and the southern curse: Framing kudzu as environmental other through discourses of fear. Southeastern Geographer, 50 (1), 110-129.

  • EU – European Union (2017). Invasive Alien Species of Union concern. Luxembourg: Publications Office of the European Union, Luxembourg. Downloaded from (Accessed 14.02.18).

  • Genovesi, P. (2005). Eradications of invasive alien species in Europe: a review. Biological invasions, 7(1), 127-133.

  • Holmes, T. P., Aukema, J. E., Von Holle, B., Liebhold, A., & Sills, E. (2009). Economic impacts of invasive species in forests. Annals of the New York Academy of Sciences, 1162(1), 18-38.

  • Horan, R. D., Perrings, C., Lupi, F., & Bulte, E. H. (2002). Biological pollution prevention strategies under ignorance: the case of invasive species. American Journal of Agricultural Economics, 84(5), 1303-1310.

  • ISSG – Invasive Species Specialist Group. Global Invasive Species Database. Retrieved from (accessed 05.40.18).

  • Kobilinsky, D. (2016). Invasive species bigger threat in developing countries. The Wildlife Society September 2, 2016. Retrieved from (Accessed 05.04.18).

  • Larson, B. M., & Kueffer, C. (2013). Managing invasive species amidst high uncertainty and novelty. Trends in Ecology & Evolution, 28(5), 255-256.

  • Lee, C. E. (2002). Evolutionary genetics of invasive species. Trends in ecology & evolution, 17(8), 386-391.

  • Lounibos, L.P. (2002). Invasions by insect vectors of human disease. Ann. Rev. Entomol., 47, 233–266.

  • Lovell, S. J., Stone, S. F., & Fernandez, L. (2006). The economic impacts of aquatic invasive species: a review of the literature. Agricultural and Resource Economics Review, 35(1), 195-208.

  • Mack, R. N., Simberloff, D., Mark Lonsdale, W., Evans, H., Clout, M., & Bazzaz, F. A. (2000). Biotic invasions: causes, epidemiology, global consequences, and control. Ecological applications, 10(3), 689-710.

  • Mooney, H. A., & Cleland, E. E. (2001). The evolutionary impact of invasive species. Proceedings of the National Academy of Sciences, 98(10), 5446-5451.

  • Narščius, A., Olenin, S., Zaiko, A., & Minchin, D. (2012). Biological invasion impact assessment system: from idea to implementation. Ecological Informatics, 7(1), 46-51.

  • Perry, D. A. N., & Perry, G. A. D. (2008). Improving interactions between animal rights groups and conservation biologists. Conservation Biology, 22(1), 27-35.

  • Phillips, B. L., Brown, G. P., Webb, J. K., & Shine, R. (2006). Invasion and the evolution of speed in toads. Nature, 439(7078), 803.

  • Pimentel, D., Zuniga, R., & Morrison, D. (2005). Update on the environmental and economic costs associated with alien-invasive species in the United States. Ecological economics, 52(3), 273-288.

  • Pyšek, P., & Richardson, D. M. (2010). Invasive species, environmental change and management, and health. Annual Review of Environment and Resources, 35, 25-55.

  • Richardson, D. M., Pyšek, P., & Carlton, J. T. (2011). A compendium of essential concepts and terminology in invasion ecology. Fifty years of invasion ecology: the legacy of Charles Elton, 409-420.

  • Richardson, D. M., Pyšek, P., Rejmánek, M., Barbour, M. G., Panetta, F. D., & West, C. J. (2000). Naturalization and invasion of alien plants: concepts and definitions. Diversity and distributions, 6(2), 93-107.

  • Sakai, A.K., Allendorf, F.W., Holt, J.S., Lodge, D.M., Molofsky, J., With, K.A., Baughman, S., Cabin, R.J., Cohen, J.E., Ellstrand, N.C. and McCauley, D.E (2001). The population biology of invasive species. Annual review of ecology and systematics, 32(1), 305-332.

  • Simberloff, D., Martin, J.L., Genovesi, P., Maris, V., Wardle, D.A., Aronson, J., Courchamp, F., Galil, B., García-Berthou, E., Pascal, M. and Pyšek, P. (2013). Impacts of biological invasions: what's what and the way forward. Trends in ecology & evolution, 28(1), 58-66.

  • Smithsonian Institute (2010). The World’s Worst Invasive Mammals. 20 December 2010. Retrieved from (accessed 22.03.18)

  • Van Driesche, J., Van Driesche, R. (2000). Nature Out of Place: Biological Invasions in the Global Age. Island Press, Washington, DC.

  • Vila, M., J. D. Corbin, J. S. Dukes, J. Pino, and S. D. Smith (2007). Linking plant invasions to global environmental change. Pages 93–102 in J. Canadell, D. Pataki, and L. Pitelka, editors. Terrestrial ecosystems in a changing world. Springer‐Verlag, New York.

  • Vitule, J. R. S., Freire, C. A., Vazquez, D. P., Nuñez, M. A., & Simberloff, D. (2012). Revisiting the potential conservation value of non-native species. Conservation biology, 26(6), 1153-1155.

  • Waldner, L. S. (2008). The kudzu connection: Exploring the link between land use and invasive species. Land use policy, 25(3), 399-409.

  • Walsh, J. R., Carpenter, S. R., & Vander Zanden, M. J. (2016). Invasive species triggers a massive loss of ecosystem services through a trophic cascade. Proceedings of the National Academy of Sciences, 113(15), 4081-4085.

  • Walther, G.R., Roques, A., Hulme, P.E., Sykes, M.T., Pyšek, P., Kühn, I., Zobel, M., Bacher, S., Botta-Dukat, Z., Bugmann, H. and Czucz, B. (2009). Alien species in a warmer world: risks and opportunities. Trends in ecology & evolution, 24(12), 686-693.

  • Williamson, M. (1996). Biological Invasions, Chapman & Hall, London.

  • Williamson, M. & Fitter, A. (1996). The varying success of invaders. Ecology 77, 1661–1666.

  • Zavaleta, E. S., Hobbs, R. J., & Mooney, H. A. (2001). Viewing invasive species removal in a whole-ecosystem context. Trends in Ecology & Evolution, 16(8), 454-459.

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