崇明岛潮间带夏季大型底栖动物多样性

The biodiversity of marobenthos of intertidal zone on Chongming Island in summer

2006年6月,在上海市崇明岛潮间带设置21个断面,进行了大型底栖动物定量定性采样调查。采集到大型底栖动物63种,其中甲壳动物29种,占总种数的46.03%;软体动物20种,占31.75%;环节动物10种,占15.87%;底栖鱼类2种;其它2种。优势种为无齿相手蟹、天津厚蟹、谭氏泥蟹、中华拟蟹守螺、堇拟沼螺、绯拟沼螺、光滑狭口螺和丝异蚓虫。大型底栖动物总平均丰度为138.28ind/m^2,平均生物量为79.11g/m^2。系统聚类分析和MDS分析结果基本吻合,可以把21个断面分为3组,崇明北部断面群、崇明东部断面群和崇明南部（含西部）断面群。Shannon-Weiner指数H′=1.85±0.528（范围0.946-2.783）,Pielou均匀度指数J=0.306±0.098（范围0.142-0.489）,Simpson优势度指数D=0.622±0.141（范围0.303-0.797）。底栖动物的种类组成、丰度、生物量、多样性指数在各断面的差异主要与盐度分布、底质及人为干扰有关。与同期的历史资料相比,底栖动物总物种数变化不大,但种类组成有所变化;优势种有所变化;丰度和生物量均有所下降;多样性指数近年来变化不大。围垦减缓使崇明潮间带底栖动物多样性有所恢复,但在人为干扰和其他因素综合影响下,原为优势种的河蚬、彩虹明樱蛤、麂眼螺、小头虫和疣吻沙蚕等的密度下降,已不再是优势种。

Chongming Island （31°25′N -31°50′N, 121°10′E -122°00′E） is the largest alluvion of China and situates in the Yangtze estuary. We investigated the Summer macrobenthos species diversity in the Chongming Island intertidal zone and the species distribution trend. Study materials were collected in June 2006 for qualitative and quantitative investigation from 21 sections in the Chongming Island intertidal zone. The Shannon-Wiener index, Pielou＇s eveness index, Simpson＇s diversity index, clustering analysis and MDS were applied to analyse the data of community structure, species assemblages, dominant species and macrobenthos abundance. In this investigation, 63 macrobenthos species were obtained, of which 29 species are crustacean （46.03%） , 20 species are mollusca （31.75%） , 10 species belong to annelida （ 15.87% ） , 2 species are dermesal fishes and 2 other species. Among dominant species were： Sesarma dehaani , Helice tientsinensis , llyrplax deschampsi , Cerithidea sinensis , Assiminea violacea, Assiminea latericea, Stenothyia glabra, Heteromastus filiformis. The average marozoobenthos abundance was 138.28 ind/m^2, and the biomass was 79.11 g/m^2. According to the clustering analysis and MDS results, the sections were divided into limnetic groups, brachish groups and hyperhaline groups situated respectively at the south, north and east （ including west） of Chongming Island. Shannon-Weiner index H＇ = 1.85 ± 0. 528 （ range 0.946 -2.783 ）, Pielou index J＇ =0.306±0.098（0. 142 - 0.489 ）, Simpson diversity index D = 0. 622 ± 0. 141 （0. 303 - 0. 797 ）. The difference of species composition, biomass, abundance and diversity indexes between the sections are caused by salinity, substrate and artificial activities. Compared with the previous data, the total species and diversity index didn＇ t change much during recent years, while species composition changed. The abundance and the biomass deceased. The slowing of diking wetland facilitatesthe biodiversity of marobenthos to convalesce in the intertidal zone. Affected by artificial activities, the runoff of Yangtze River and other factors, the previously dominant species are no longer dominant, and their abundace and distribution area is descreasing. Affected species include Corbicula fluminea, Moerella iridescens, Rissoina sp. , Capitella capitata, and Tylorrhynchus heterochaetus.