Invasive or Investment?

All species have evolved adaptive mechanisms that allow them to survive given the conditions, resources, competitors and consumers of their native ecosystems. Some species adapt by having a broad range of tolerance to abiotic conditions, using a variety of environmental resources, having high growth or reproductive rates or altering the environment to a state more favorable to their own growth and reproduction. When introduced into ecosystems where conditions are favorable and biological controlling factors are absent, such species may exhibit invasive behavior, eventually dominating the original ecosystem and causing severe environmental and economic damage.

Human actions have greatly accelerated the global dispersal of species. In some cases the introduction is accidental, but in many cases non-native species have been introduced intentionally for commercial cultivation, landscaping or erosion control. Often, the value of a species as a cultivar arises from the very characteristics that allow it to become invasive. Arundo donax, known commonly as giant reed, is an example of such a species.

A. donax has been cultivated for millennia in the Mediterranean area for diverse uses including reeds for musical instruments (Perdue, 1958). A. donax has a very high growth rate, producing as much as 20 tons per hectare of dry biomass (Perdue, 1958). Because of its high growth rates, commercial plantations have been proposed in Florida to cultivate "e-grass", a pseudonym for A. donax, for energy to produce electricity (Nature and Technology, n.d.) and in Northern California for paper pulp (A Paperless Society, 2002), (Richards, 2002).

At the same time, a $20 million project is underway in California to eradicate A. donax in the Santa Ana watershed (Arundo removal, 2002). Introduced in the Los Angeles area of California nearly 200 years ago for erosion control (Hoshovsky, 1987), A. donax has since become invasive throughout the warmer coastal freshwaters of the United States and is now considered the foremost threat to riparian ecosystems in southern California (Bell, 1997).

References

• Nile Fiber and Samoa Pacific Cellulose Make History With Successful Commercial Pulp Run of Arundo donax, March 10, 2002. Retrieved October 29, 2003 from the Nile Fiber Pulp and Paper, Inc. website: http://www.nilefiber.com/press_release_article2.htm .
• Arundo Removal in the Santa Ana Watershed, July, 2002. Retrieved October 29, 2003 from the Team Arundo and Santa Ana Watershed Project Authority website: http://www.sawpa.org/arundo/documents/ArundoRemovalJuly2002.pdf .
• Bell, G., 1997. Ecology and management of Arundo donax, and approaches to riparian habitat restoration in Southern California. In Brock, J. H., Wade, M., Pysek, P., and Green, D. (Eds.): Plant Invasions: Studies from North America and Europe. Blackhuys Publishers, Leiden, The Netherlands, pp. 103-113. Available from http://teamarundo.org/ecology_impacts/arundo_ecology.html .
• Hoshovsky, M., 1987. Arundo donax. Element Stewardship Abstract. The Nature Conservancy, San Francisco, CA, 10 pp. Available from http://tncweeds.ucdavis.edu/esadocs/documnts/arundon.html .
• Nature and Technology Working Together, (n.d.). Retrieved October 25, 2003 from the Biomass Investment Group, Inc. website: http://www.egrass.com/.
• Perdue, R.E., 1958. Arundo donax - source of musical reeds and industrial cellulose. Economic Bot. 12: 368-404.
• Richards, Bill, October 16, 2002. Arundo has two lives. Special to the Wall Street Journal. Retrieved October 29, 2003 from a posting on the Biomass Investment Group, Inc. website: http://www.egrass.com/pr02.htm/.