Salinity and Inundation Tolerance of Phragmites australis ssp. americanus: A Greenhouse Experiment and Field Study on a Tributary of the Chesapeake Bay

Abstract

Natural vegetation communities of tidal and non-tidal wetlands are threatened by invasive species, e.g. Phragmites australis (Cav.) Trin. Ex Steud., resulting in diversity losses and declines in wetland services. The native lineage of Phragmites, Phragmites australis ssp. americanus Saltonstall, P. M. & Soreng could be a valuable addition to species currently used in restoration projects aimed at increasing wetland services. However, tolerances of native Phragmites to environmental conditions are uncertain. Salinity and water level tolerances were investigated by monitoring growth of adult plants, established from rhizomes, under varying water and salinity levels in a greenhouse experiment and an observational study. Results show salinity levels above 5 ppt significantly limited growth of native Phragmites regardless of water level indicating appropriate restoration use across the marsh platform of fresh and oligohaline systems. Educational materials and demonstration sites were created to improve field identification of native Phragmites.