Rapid Population Explosion of Exotic Variety of Phragmites australis
Ann Arbor, Mich. — Phragmites australis, or Common Reed, is a tall cane-like grass that grows in aquatic, semi-aquatic and terrestrial habitats. Phragmites has been rapidly expanding throughout the wetlands of Long Point, Lake Erie; this expansion is mostly due to an invasive exotic variety of the species.
"This expansion has caused concern among biologists and the general public because Phragmites is thought to degrade waterfowl habitat and reduce biodiversity", states Scott Petrie, the Research Director of the Long Point Waterfowl and Wetlands Research Fund. "However, before taking action to control the plant, it was important to actually measure the rate at which Phragmites is spreading throughout lower Great Lakes wetlands. Furthermore it has not yet been proven that it compromises wildlife habitat."
Petrie and fellow researchers addressed the first of these questions by tracking the rate at which Phragmites had been expanding on Long Point's wetlands over the past 50 years. Although Phragmites has been present since at least the 1940s, it has only been expanding rapidly since the early to mid-1990s. They found that 90% of the stands studied at Long Point were of a non-native variety of Phragmites that has invaded from Europe. It seems that the observed rapid expansion is a direct result of this exotic introduction; it is possible that its expansion has been accelerated by increased temperatures and lower Great Lakes water levels.
"Given the invasive nature of the exotic genotype, combined with future global warming predictions, Phragmites will likely continue to rapidly expand throughout lower Great Lakes coastal wetlands," states Petrie.
Original Publication Information
Results of this study, "Historical Distribution and Abundance of Phragmites australis at Long Point, Lake Erie, Ontario," are reported by Kerrie L. Wilcox, Scot A. Petrie, Laurie A. Maynard and Shawn W. Meyer in the latest issue (Volume 29, No. 4, pp. 664-680) of the Journal of Great Lakes Research, published by the International Association for Great Lakes Research, 2003
Contacts
For further information about the study, contact Scott A. Petrie, Long Point Waterfowl and Wetlands Research Fund, Bird Studies Canada, P.O. Box 160 Port Rowan, ON, N0E 1M0; spetrie@bsc-eoc.org; (519) 586 3531.
For information about the Journal of Great Lakes Research, contact Marlene Evans, Editor, National Water Research Institute, 11 Innovation Boulevard, Saskatoon, SK, S7N 3H5, Canada; marlene.evans@ec.gc.ca; (306) 975-5310.
Since 1967, IAGLR has served as the focal point for compiling and disseminating multidisciplinary knowledge on North America's Laurentian Great Lakes and other large lakes of the world and their watersheds. In part, IAGLR communicates this knowledge through publication of the Journal of Great Lakes Research, available to members in print and electronic form. A searchable archive of the journal is available online and includes the abstracts of articles from the journal's inception in 1975 through the most recent issue. In addition, complete articles are available to members who have signed up for an electronic subscription.
