THE EFFECTS OF SALINITY AND WATERLOGGING ON THE GROWTH AND CATION UPTAKE OF SALT MARSH PLANTS

Abstract

S ummary Festuca rubra, Juncus gerardii, Armeria maritima, Plantago maritima, Aster tripolium, Triglochin maritima, Puccinellia maritima and Salicornia europaea from a salt marsh near Portaferry, County Down, were grown on drained and waterlogged salt marsh soils under saline and non‐saline conditions. Shoot and root yields and the concentrations of sodium, potassium, calcium, magnesium, manganese and iron in the shoots were determined after a 2‐month growing period. The tolerance of the plants to waterlogging and salinity differed in a way which was correlated with their position on the salt marsh ecotone. The growth of upper marsh species, but not that of lower marsh species, was strongly limited by both salinity and waterlogging. Only Salicornia europaea gave its maximum yield on the saline treatments and only Puccinellia maritima showed a preference for waterlogged soils. Reduced yields on the saline treatments were associated with large increases in shoot sodium concentrations but in general, salinity and waterlogging had little effect on shoot cation concentrations. It is suggested that factors other than the greater availibility of iron and manganese on araerobic salt marsh soils are involved in determining species distribution along the salt marsh ecotone.