滩涂沉积物中叶绿素a浓度与沉积特性的关系

2005年4，5，10和12月在崇明东滩中潮带光泥滩(藻类盐渍带)内靠近海三棱藨草( Scripus mariqueter )带选择一区域，沿高程方向选取3个断面，每个断面选取了3个样点，进行了表层沉积物叶绿素a的浓度和粒径组成的观测研究.结果表明，研究区域表层沉积物中叶绿素a的浓度4，5月份较高，分别为(5.997±0.803) μg·g^-1和(2.356±0.298) μg·g^-1，12月份最低，为(0.571±0.091) μg·g^-1；表层沉积物中细颗粒物质(＜50 μm)含量从4月到12月也有减少的趋势，春季4月份最高，为(91.0±5.44)%，冬季12月份最低，为(59.8±11.95)%.对4个月份样品的叶绿素a浓度与细颗粒物质含量进行相关关系分析，研究结果显示它们之间存在线性正相关( r=0.693，P=0.012 )，表明细颗粒物质的含量与叶绿素a浓度之间存在着一定的相互促进作用.此外，由于光的限制，沉积物中叶绿素a的浓度主要分布在表层1 cm内，且海三棱藨草与光滩过渡带中光滩表层沉积物中叶绿素a的浓度远大于同高程的海三棱藨草内.

Study on Relation between Variation of Chlorophyll a Concentration and Sediment Grain Size on an Intertidal Flat

The chlorophyll a concentration and grain size in the sediment of an intertidal flat, as well as their relations were studied based on experiment data observed in the mudflat of Chongming Dongtan in Changjiang Estuary, where samples from three transects were taken during April, May, October and December in 2005. The results showed that there were remarkable seasonal variations of chlorophyll a concentrations and grain size at the surface of the mudflat, i.e., the chlorophyll a concentrations were higher in April ［(5.997±0.803 ) μg·g^-1］ than in December ［(0.571±0.091) μg·g^-1］, and the grain size had the similar trend of seasonal variations. The correlation between chlorophyll a concentrations and fine grained sediment content was significant at the 0.05 level ( r=0.693, P=0.012). Moreover, due to the light limitation, the chlorophyll a concentrations at the surface of the sediments were high, and rapidly decreased with the depth, and also were higher on the sediments surface in bare tidal flat than in Scripus mariqueter zone of the transition area.