Little information is available on As contamination dynamics in the soil-plant systems of wetlands. Total arsenic (As) in soil and plant samples fromSuaeda salsaandPhragmites australiswetlands was measured in the Yellow River Estuary (YRE) in summer and autumn of 2007 to investigate the seasonal changes in As concentrations in different wetlands. The results showed that soil As levels greatly exceeded the global and regional background values. As levels in soil and the roots and stems of both types of plants were much higher in summer than in autumn, whereas leaf As showed higher level in autumn. Soil sulfur was the main factor influencing As levels inSuaeda salsawetlands, whereas soil porosity was the most important factor forPhragmites australiswetlands. The contamination factor (CF) showed moderately to considerably polluted levels of As in both wetland soils. Plant roots and leaves ofSuaeda salsahad higher As concentrations and biological concentration factors (BCFs) than stems, while the leaves and stems ofPhragmites australisshowed higher As levels and BCFs than roots. Compared toPhragmites australis,Suaeda salsagenerally showed higher translocation factor (TF), while TF values for both plant species were higher in summer than in autumn.
Effects of sediment burial disturbance on seedling survival and growth of Suaeda salsa in the tidal wetland of the Yellow River estuary
