宁波南韭山附近海域浮游植物的群落结构

Community structure of phytoplankton in Nan Jiushan Sea Area of Ningbo

2012年4月、7月、10月和2013年1月,对宁波南韭山附近海域15个站点的浮游植物的种类组成、丰度分布进行了调查,分析了浮游植物优势种组成、多样性指数及其群落结构。共鉴定出浮游植物7门68属157种,其中硅藻门有40属113种,占总种数的71.9%,为优势类群。该海域优势种22种,全年优势种为星脐圆筛藻,浮游植物种类数呈现环岛海域高于岛外海域的趋势,数量变化由多到少依次为：秋季〉夏季〉冬季〉春季。浮游植物丰度分布具有明显的季节差异,全年丰度最高点是夏季S3（700.00ind/L）,最低点冬季S5（11.50 ind/L）;丰度数量变化由多到少为秋季〉夏季〉春季〉冬季。生物量大小为秋季〉春季〉夏季〉冬季。海域各站点物种丰富度指数（d）、物种多样性指数（H＇）、均匀度指数（J）、生态优势度指数（d＇）的波动范围分别为1.70~5.12、1.95~4.06、0.67~0.84、3.38~13.00,表明调查期间南韭山附近海域物种多样性高,群落结构稳定,其中秋季的物种多样性最高。

In April, July, October 2012 and January 2013, investigations were conducted on the species composition and abundance distribution of phytoplankton in Nan Jiushan Sea Area. Based on the investigation data, the phytoplankton＇ s dominant species,biological index, and community structure were analyzed. A total of 157 species of 68 genera belonged to 7 phyla were identified, most of which, 113 species belonged to 40 genera of diatoms accounted for 71.9%. The dominant species were 22, and Coscinodiscus asteromphalus was the dominant species in the whole year. The species number had a trend decreasing from the inner to the outer of the Nan Jiushan Archipelago and the quantity from more to less ： Autumn 〉 Summer 〉 Winter 〉 Spring. There was an obvious seasonal change in the abundance, being the highest （700.00 ind/L） in summer and the lowest （11. 50 ind/L） in winter; from more to less： the abundance was Autumn 〉 Summer 〉 Spring 〉 Winter and the biomass was Autumn 〉 Spring 〉 Summer 〉 Winter. The abundance index （d） ranged from 1.70 to 5.12; the diversity index（H＇） and uniformity index（J） varied from 1.95 to 4.06 and 0.67 to 0.84; the predominant index （d＇）ranged from 3.38 to 13.00. Through the analysis of the biological index, it can be considered that the species diversity is high, and the phytoplankton community structure is stable, particularly in Autumn.