Seeds contribute strongly to the spread of the invasive genotype of the common reed (Phragmites australis)
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The introduced subspecies of the common reed (Phragmites australis (Cav.) Trin. ex Steud. subsp. australis; Poaceae) is considered one of the most invasive plants in North American wetlands. Given its relatively low seed set and its tremendous capacity to spread via stolons or rhizomes, it has generally been thought that the spread of vegetative diaspores was responsible for the establishment of new populations. To test this hypothesis, we sampled a single plant from each of 345 visually-distinct common reed stands located along the shores of Lake St. François (southern Quebec, Canada). With a set of six nuclear microsatellite markers, we distinguished 134 different genotypes. The number of individuals sharing the same genotype ranged from one to 16, and averaged 2.1. Most genotypes were encountered only once. We examined the spatial distribution of the most frequent genotypes and found little evidence of clusters along the lakeshore. These data contradict the hypothesis that a common reed invasion is initiated by the introduction of vegetative diaspores from a few clones. Rather, they clearly support the alternative hypothesis that seeds were the primary diaspores responsible for the establishment of common reed populations.
KeywordsCommon reed Haplotype M Lake Phragmites australis Seed Wetland
This research was financially supported (grants to F. Belzile and C. Lavoie; scholarship to J. Labbé) by the Natural Sciences and Engineering Research Council of Canada, and by the Frontenac National Park. We are grateful to M. Jean and A. Saint-Louis for laboratory assistance, and to J. Dubé for his help with statistical analyses.
- Cressie NAC (1993) Statistics for spatial data, 2nd edn. Wiley, New YorkGoogle Scholar
- Hunter KL, Fox DA, Brown LM, Able KW (2006) Responses of resident marsh fishes to stages of Phragmites australis invasion in three mid Atlantic estuaries. Estuar Coast 29:487–498Google Scholar
- Koppitz H, Kühl H, Hesse K, Kohl J-G (1997) Some aspects of the importance of genetic diversity in Phragmites australis (Cav.) Trin. ex Steudel for the development of reed stands. Bot Acta 110:217–223Google Scholar
- Lavoie C, Jean M, Delisle F, Létourneau G (2003) Exotic plant species of the St. Lawrence River wetlands: a spatial and historical analysis. J Biogeogr 30:537–549Google Scholar
- LeBlanc M-C (2008) Quels sont les facteurs qui expliquent l’envahissement des berges du Grand lac Saint-François par le roseau commun (Phragmites australis)? M. ATDR Thesis, Université Laval, Quebec CityGoogle Scholar
- Mal TK, Narine L (2004) The biology of Canadian weeds. 129. Phragmites australis (Cav.) Trin. ex Steud. Can J Plant Sci 84:365–396Google Scholar
- Ministère du Loisir, de la Chasse et de la Pêche du Québec (1986) Parc de Frontenac: le plan directeur. Ministère du Loisir, de la Chasse et de la Pêche du Québec, Direction de l’aménagement, Service des plans directeurs, Quebec CityGoogle Scholar
- Robitaille A, Saucier J-P (1998) Paysages régionaux du Québec méridional. Publications du Québec, Sainte-FoyGoogle Scholar
- Société des établissements de plein air du Québec (2005) Suivi des populations de roseau commun (Phragmites communis) le long du lac Saint-François. Société des établissements de plein air du Québec, Quebec CityGoogle Scholar
- Warren RS, Fell PE, Grimsby JL, Buck EL, Rilling GC, Fertik RA (2001) Rates, patterns, and impacts of Phragmites australis expansion and effects of experimental Phragmites control on vegetation, macroinvertebrates, and fish within tidelands of the lower Connecticut River. Estuaries 24:90–107CrossRefGoogle Scholar