Wang Wei-Wei, Li Dao-Ji, Gao Lei
State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.
Huan Jing Ke Xue. 2009 Nov;30(11):3209-17.
The variations of nutrients in pore water of salt marsh sediment were surveyed in the middle intertidal zone of Chongming Dongtan during August 2007 to May 2008 to identify plant impact on nutrients distribution. The results show that NH4(+) -N and PO4(3-) -P concentrations are lower in pore water of Spartina alterniflora and Phragmites australis zones than in bare flat, and specially, NH4(+) -N concentrations in summer and autumn decrease by one more orders of magnitude. Compared to winter, nutrients concentrations are obviously higher during the period of plant growth, and plant biomass is clearly correlative to nitrogen and phosphorus. Vegetation growth influences nitrogen content intensively. NH4(-) -N concentrations in Spartina alterniflora and Phragmites australis zones are 44.21 and 74.38 micromol x L(-1) respectively, distinctly lower than that in bare flat and Scirpus mariquete zone (340.14 and 291.87 micromol x L(-1) respectively). Moreover, NO(x)(-) -N concentration is one to two order(s) of magnitude lower than NH4(+) -N, and its highest value exists in Phragmites australis zone (5.94 micromol x L(-1)). The results of molecule diffusive flux of nutrients in the surface sediment-overlying water interface indicate that marsh sediment is the source for SiO3(2-) -Si, NH4(+) -N and PO4(3-) -P, and the rank for NO(x)(-) -N (NO3(-) -N + NO2(-) -N), and NO(x)(-) -N flux from overlying water to sediment [16.23 micromol x (m2 x h)(-1)] is higher than NH4(+) -N flux from sediment to overlying water [15.53 micromol x (m2 x h)(-1)]. Vegetation growth accommodates nutrient structure of the estuarine ecosystem by affecting sediment-water interface mass flux and nutrient ratios in pore water and overlying water.
2007年8月至2008年5月，对崇明东滩潮间带中部盐沼沉积物孔隙水中的养分变化进行了调查，以确定植物对养分分布的影响。结果表明，互花米草带和芦苇带孔隙水中的NH4(+) -N和PO4(3-) -P浓度低于光滩，特别是夏秋季节NH4(+) -N浓度降低了一个多数量级。与冬季相比，植物生长期间养分浓度明显较高，且植物生物量与氮、磷明显相关。植被生长对氮含量影响较大。互花米草带和芦苇带的NH4(-) -N浓度分别为44.21和74.38微摩尔/升，明显低于光滩和海三棱藨草带（分别为340.14和291.87微摩尔/升）。此外，NO(x)(-) -N浓度比NH4(+) -N低一至两个数量级，其最高值出现在芦苇带（5.94微摩尔/升）。表层沉积物-上覆水界面养分分子扩散通量的结果表明，盐沼沉积物是SiO3(2-) -Si、NH4(+) -N和PO4(3-) -P的源，而NO(x)(-) -N（NO3(-) -N + NO2(-) -N）的情况则相反，上覆水向沉积物的NO(x)(-) -N通量[16.23微摩尔/(平方米·小时)]高于沉积物向上覆水的NH4(+) -N通量[15.53微摩尔/(平方米·小时)]。植被生长通过影响沉积物-水界面质量通量以及孔隙水和上覆水中的养分比例，调节了河口生态系统的养分结构。
