崇明东滩底栖动物群落与潮滩高程的关系

东滩低潮滩以软体动物中的麂眼螺、泥螺等占优势；中潮滩以软体动物的麂眼螺、霍甫水丝蚓、彩虹明樱蛤及双翅目幼虫为优势；高潮滩的优势种为绯拟沼螺、双翅目幼虫以及一些大型蟹类如无齿相手蟹和天津厚蟹等。在生物量方面，中潮滩的底栖动物生物量最高为139．8g／m^2，其次为高潮滩，其生物量为109．7g／m^2，生物量最低的为低潮滩，仅有61．77g/m^2，平均生物量排序为中潮滩〉高潮滩〉低潮滩。在多样性方面,3个潮带也以中潮滩最高，其次是高潮滩和低潮滩。底栖动物的这种分带情况与3个潮带特有生境密切相关,沿高程梯度,底栖动物群落呈现出明显的空间生态系列格局。低潮滩代表了潮滩湿地演替的初级阶段。中潮滩底栖动物种类数和多样性都较高,此带代表了潮滩湿地演替的较高阶段。高潮滩显示了向陆生群落演变的趋势。

Relationship between Macrobenthos Community and Tidal Flat Elevation in Chongming Dongtan

There was much relation between the structure of macrobenthos community and elevation of tidal flat. Rissoina sp., Bullamya purificata and Corbicula fluminea were dominant in low tidal flat; Rissoina sp., Limnodrius hoffmeisteri, Moerella iridescens and Diptera.sp. were dominant in middle tidal fiat; Assiminea latericera, Diptera.sp. and some other big crabs were dominant in high tidal fiat. The biomass of macrobenthos was 139.8 g/m^2 in middle tidal fiat： the biomass of macrobenthos was 109.7g/m^2 in high tidal fiat; the biomass of macrobenthos was 61.77g/m^2 in low tidal fiat. The value of Shannon-Wiener＇s index was following that： middle tidal fiat〉high tidal flat 〉low tidal fiat. There was a clear space ecological pattern of macrobenthos community along the elevational gradients of tidal fiat in the Dongtan, which reflected the success process of macrobenthos community with the passage of time and difference of its tolerance to environmental factors.