长江口潮下带大型底栖动物群落特征

2013年至2014年,对长江口及其邻近水域进行了8个航次104个站点的潮下带大型底栖动物调查,通过Shannon-Wiener多样性指数(H)、Pielou种类均匀度(E)、种类丰度(D)和优势度指数(Y)等指标参数分析了大型底栖动物的物种多样性,应用等级聚类和非度量多维标度排序分析了底栖动物群落结构。结果显示,2013年共采获大型底栖动物49种,2014年40种,每年不同季节种类更替明显。2013年大型底栖动物丰度和生物量最高分别出现在春季和秋季,2014年分别为冬季和夏季,不同年份不同季节的生物量和丰度明显不同。不同年份的特征种均以甲壳动物类群为主,鱼类优势种增多。2013年秋季和2014年春季的大型底栖动物相对于同年度其他季节有更高的多样性,年度变化上多样性指数整体增高。群落结构分析表明,2013年夏秋冬聚为1组,春季为1组;2014年春夏秋聚为1组,冬季为1组。ABC曲线结果显示,潮下带大型底栖动物群落在2013年四季受到中度干扰,2014年春夏秋受干扰不明显,冬季受到中等程度以上的干扰。本研究结果为长江口生态环境保护及修复提供了理论依据。

Characteristics of macrobenthic community in subtidal zones of the Yangtze River estuary

The present study investigated the species composition,dominance and characteristics of macrobenthic fauna within 13 sampling stations from eight survey cruises in Yangtze River estuary during February,May,August and November,in 2013 and 2014.The Shannon Wiener diversity index (H),Pielous species evenness (E),species abundance (D),dominance index (Y) were used to evaluate Yangtze estuary community characteristics.In addition,the community structures of macrobenthic fauna were analyzed by hierarchical cluster and non-metric sort multidimensional scaling (NMDS).The results showed that a total of 49 species of large benthic animals were obtained in 2013,and 40 species were collected in 2014.The temporal variation of macrobenthos in different seasons changed obviously in the same year,and the total number of species decreased in 2014.The highest abundance and biomass appeared in the spring and autumn,2013 and in winter and summer,2014.The biomass of different seasons was obviously different in 2013 and 2014.Crustaceans were characteristic of macrobenthos in both 2013 and 2014,and the dominant species belonging to fish increased.Higher diversity was observed in the autumn,2013 and in the spring,2014 comparzed to the other seasons in the same year.Generally,and the diversity index showed an increasing tendency during the investigation of two years' period.Hierarchical cluster analysis and NMDS analysis showed that the macrobenthic community of the Yangtze River estuary constituted two groups in 2013,and community in the summer,autumn and winter were grouped from that in spring.In 2014,community in spring,summer and autumn were clustered,and was separated from community in the winter.ABC curve showed that macrobenthic communities in subtidal zones were moderately affected in the four seasons in 2013.In contrast,in 2014,no significant effect on macrobenthic community was observed in the spring,summer and autumn,and macrobenthic community was only affected with heavily moderate interference in winter.The tendency in decreasing interference was observed during the investigation period.