[Analysizing and quantitatively evaluating the organic matter source at different ecologic zones of tidal salt marsh,...

The indicators including TOC, TN, C/N, delta 13C and delta 15N of surface sediments, core sediments and plants of tidal salt marshes in North Jiangsu Province are analysized.Subsequently, distribution regularities of these measurement indicators are discussed, and the biogeochemistry processes between sediments and plants are also analysized. Lastly, the organic matter sources of different ecologic zones in tidal salt marsh are evaluated, and the organic matter accumulations in different ecologic zones induced by their plants are also compared. The results indicate that TOC, TN, C/N and delta 13C show obviously zonal distribution. The organic matter sources are dominated by marine input in silt flat, Artemisia schrenkiana flat, and the transition zone between silt and Spartina alterniflora flat, and controlled by terrigenous input in Spartina alterniflora flat. Spartina alterniflora plays an important role in the accumulation of organic matter in the whole tidal salt marshes ecosystem. In study area, the annually increased TOC, organic matter and TN in Spartina alterniflora flat, Artemisia schrenkiana flat and reed flat respectively reach 6 451t, 16 595t and 536t. The amount of TOC, organic matter and TN accumulated in Spartina alterniflora flat are more than those in other ecological zones, which show that the Spartina alterniflora flat exert nonreplaceable effect on the material cycle and exchange in the whole tidal salt marshes ecosystem.