秋、冬季北部湾浮游介形类群落多元分析

根据对北部湾生态环境综合调查所采集的浮游动物样品，对北部湾秋、冬季浮游介形类组成及群落结构进行了多元分析.结果表明，测区内浮游介形类种类为11种，分属于低盐暖水类群、广温广盐类群和高温高盐类群3个生态类群；海区内的平均丰度较低，其中针刺真浮萤数量最多，为海区的绝对优势种，左右着整个北部湾浮游介形类的数量.聚类分析和MDS分析表明，北部湾浮游介形类为一个结构相对稳定的群落，秋、冬季可看成是一个群落的2个亚群；对各聚类组的丰度与水温、盐度相关分析表明，水温、盐度对浮游介形类群落结构变化所产生的作用较小，但存在一定的规律性；在冬季，底层温盐对群落Ⅱ产生显著影响.

Multivariate analysis of planktonic Ostracoda communities during autumn and winter in the Beibu Gulf

Base on the zooplankton samples collected in two cruises for studying the change tendency of ecological environment in the Beibu Gulf, planktonic Ostracoda communities in autumn and winter in the Beibu Gulf were investigated by multivariate analysis. A total of 11 planktonic Ostracoda species were identified and grouped into three ecotypes, i.e., Huposaline and warm-water group, Eurythermal and eurysaline group, as well as Hyperthermal and hysaline group. The average abundance of all species was low, and Euconchoecia aculeate was the most abundant one. Based on the cluster analysis and multidimensional scaling analysis, planktonic Ostracoda in the Beibu Gulf was a community of stable structure, while in autumn and winter, the community also could be divided into two different sub-communities. To understand the relationship between the community structure and the environmental factors, correlation coefficients for the abundance and the environmental factors were calculated. It indicated that water temperature and salinity had tiny impact on planktonic Ostracoda communities, but there was some rule in its change rhythms. Sub-water temperature and salinity had strong impact on community II in winter.