文摘
We investigated the Korean Phragmites australis (haplotype P) distribution patterns and their association with environmental factors in estuaries with (Goseong) and without (Guman) a dike. The intertidal wetland of the Guman River Estuary has a flooding duration of 25% to 68% (average 40%), a range common to Phragmites habitats around the world. Porewater salinity in the Phragmites habitat of the Guman varied with the tides. Salinity of the overlying water influenced the salinity of pore-water only if flooding was above a certain height (overlying water depth of about 30 cm). High salinity was frequently observed in overlying water and pore-water of the Guman but the Phragmites may be able to survive with periodic exposure to freshwater, which relieves high salinity stresses. However, Phragmites experienced limited growth in some regions where flooding frequency was high but freshwater influence was low. Continuous measurement (two weeks) of pore-water salinity suggests that the salinity near the Phragmites rhizosphere is determined by the balance between the tidal and freshwater influences. Phragmites in the Goseong River Estuary was found at elevations about 100 cm lower than in the Guman and Phragmites growth was larger in the Goseong than in the Guman. We hypothesized that lower flooding duration and pore-water salinity, resulting from dike construction, allowed Phragmites to expand into lower elevation areas in the Goseong. The current study demonstrates the effects of coastal developments involving salinity structure and flooding duration changes on Phragmites distribution.