MEPS 298:1-8 (2005)  -  doi:10.3354/meps298001

Salt tolerance underlies the cryptic invasion of North American salt marshes by an introduced haplotype of the common reed Phragmites australis (Poaceae)

Edward A. Vasquez1, Edward P. Glenn1,*, J. Jed Brown2, Glenn R. Guntenspergen3, Stephen G. Nelson1

1Environmental Research Laboratory, 2601 East Airport Drive, Tucson, Arizona 85706, USA
2Delaware River Fisheries Coordinator, US Fish and Wildlife Service, 2610 Whitehall Neck Road, Smyrna, Delaware 19977, USA
3US Geological Survey, USGS Patuxent Wildlife Research Center, 12100 Beech Forest Road, Suite 4039, Laurel, Maryland 20708-4039, USA
*Corresponding author. Email:

ABSTRACT: A distinct, non-native haplotype of the common reed Phragmites australis has become invasive in Atlantic coastal Spartina marshes. We compared the salt tolerance and other growth characteristics of the invasive M haplotype with 2 native haplotypes (F and AC) in greenhouse experiments. The M haplotype retained 50% of its growth potential up to 0.4 M NaCl, whereas the F and AC haplotypes did not grow above 0.1 M NaCl. The M haplotype produced more shoots per gram of rhizome tissue and had higher relative growth rates than the native haplotypes on both freshwater and saline water treatments. The M haplotype also differed from the native haplotypes in shoot water content and the biometrics of shoots and rhizomes. The results offer an explanation for how the M haplotype is able to spread in coastal salt marshes and support the conclusion of DNA analyses that the M haplotype is a distinct ecotype of P. australis.


KEY WORDS: Salinity tolerance · Invasive species · Phragmites australis · Salt marshes


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