南麂列岛冬夏季潮间带大型底栖生物群落结构

Community structure of macrobenthos in the intertidal zones of Nanji Islands in winter and summer

分别于2010年2月与8月对南麂列岛4条潮间带断面的大型底栖生物进行了调查研究。共鉴定出大型底栖生物125种,其中软体动物72种,大型藻类23种,甲壳动物13种,多毛类10种,棘皮动物4种,其他3种。冬季大型底栖生物种类共72种,生物量(3 941.22±2 870.13)g/m^2,丰度(1 275.44±749.37)ind./m^2;夏季生物种类共93种,生物量(4 521.69±3 473.66)g/m^2,丰度(2 099.07±1 074.82)ind./m^2;不同季节的群落优势种无明显差异。各断面的Shannon-Wiener多样性指数在1.62~2.95之间,平均为2.50±0.46;Margalef丰富度指数在1.99~5.88之间,平均为4.81±1.31;Pielou均匀度指数在0.60~0.77之间,平均为0.71±0.06;Simpson优势度指数在0.71~0.92之间,平均为0.86±0.08。运用ABC曲线、等级聚类和MDS对大型底栖生物群落结构进行分析发现:岩礁质3条断面的群落结构在不同季节存在一定差异,但相似度均大于50%,泥质的国姓岙断面冬季和夏季则分别为两个群落。除人类活动较为频繁的国姓岙断面群落结构受到中等程度的扰动外,其他断面的大型底栖生物群落结构较为稳定。

The investigation was conducted at four sections of Nanji Islands in February and August 2010.One hundred and twenty five species were indentified,including 72 species of molluscs,23 of macroalgaes,13 of carapaces,10 of annelids,4 of echinoderms and 3 others.72 species of macrobenthos were collected in winter and 93 species in summer,the average biomass and inhabit density were 3 941.22 ± 2 870.13 g/m2,1 275.44 ± 749.37 ind./m2 and 4 521.69 ± 3 473.66 g/m2,2 099.07 ± 1 074.82 ind./m2,respectively.The dominant species in different seasons have no significant change.The index of Shannon-Wiener’ s biodiversity was from 1.62 to 2.95,the average being 2.50 ± 0.46.The Margalef’s species richness was from1.99 to 5.88,the average being 4.81 ± 1.31.The Pielou’ s evenness was from 0.60 to 0.77,the average being 0.71 ± 0.06.The Simpson’s dominance was from 0.71 to 0.92,the average being 0.86 ± 0.08.Upon analysis of the macrobenthos community structure by ABC curve,hierarchical clustering analysis and MDS diagrams,the similarity index of community structure between three rocky sections in different seasons were all higher than 50%,and lower than 10% between the only muddy section in winter and summer.The section in Guoxing’ao has the lowest community structural stability,seriously affected by the activities of fishermen.