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2006年6月(夏季)和12月(冬季)分别对长江口九段沙湿地潮滩底栖微藻的分布状况进行了调查,估算了湿地内各主要初级生产者的生产力并进行了比较.结果显示分布于该盐沼湿地的底栖微藻在光照条件下主要聚集于沉积物表层,形成其生物量随深度增加而迅速减少的垂直分布模式,并随滩面植被盖度从大到小的顺序呈现为:光滩、蔗草区、米草区≈芦苇区的水平分布特征.九段沙湿地中单位面积上底栖微藻的生物量远高于上覆水中浮游植物的生物量,其单位面积生产力也显著高于后者,表明底栖微藻在源自单胞藻的湿地有机产出中占有主导地位.九段沙湿地中底栖微藻总生物量远低于地表维管植物,其生物量仅占潮滩初级生产者总生物量的约0.41%,所产出的有机质却达到潮滩总初级生产力约16.53%,意味着这种高营养、易摄取的有机产出有能力成为维持该湿地生态系统的重要食物来源之一.“,”The observation of vertical and horizontal distribution of microphytobenthos (MPB) living on tidal flats,and the estimate of the contribution of the dominant primary producers to total primary production have been carried out in the Jiuduansha salt marshes of the Changjiang Estuary in June (summer) and December (winter) of 2006. MPB concentrate on the surface of the sediments under illumination,and its biomass decrease rapidly with depth. Significant variations of chlorophyll a concentrations in the surface sediments are found between tidal flats covered by different vegetations,following the sequence of bare flat＞ Scirpus mariqueter region＞ Spartina alterniflora region≈ Phragmetis australis region. The biomass and production of MPB are much higher than phytoplankton in the overlaying water column,indicating MPB dominate the algal production in these salt marshes. Although the biomass of MPB are much lower than vascular plants,and only account for 0.41% of total biomass of primary producers in Jiuduansha,MPB contribute 16.53% of total primary production to the ecosystem here. Considerable production of MPB makes this nutritious and digestible producer may play an important role in maintaining this salt marsh ecosystem.