乳山湾外海夏季大型底栖动物分布与环境因子的典范对应分析

Canonical Correspondence Analysis on Macrobenthos Community in Summer and Its Environment in the Offshore Water of Rushan Bay

应用典范对应分析(Canonical correspondence analysis,CCA)研究了乳山湾外海21个样点中的32种大型底栖动物与包括化学耗氧量、溶解氧等在内的11个沉积物和底层水体环境因子间的相关关系.作出种类分布与环境因子关系的二维排序图,排序图直观地反映了主要大型底栖动物种类分布与环境因子间的关系.排序图中环境因子与前两个排序轴的相关系数大小表明,总氮、溶解氧、盐度、pH、水深和总磷是影响乳山湾外海大型底栖动物群落分布的主导因素.排序图还揭示了大型底栖动物物种对生态环境的需求以及它们在不同资源维上的生态分化现象,不同生境中大型底栖动物分布的种类不同.根据对环境因子的生态需求不同,32种大型底栖动物可分为6组:组Ⅰ,8种,分布在高总氮生境;组Ⅱ,4种,分布在高溶解氧、高盐度、低总氮生境;组Ⅲ,10种,分布在水浅、高pH生境;组Ⅳ,4种,分布在水深、低pH生境;组Ⅴ,仅1种,分布在高总磷生境;组Ⅵ,5种,分布在水深、低总磷生境.

By canonical correspondence analysis （CCA）, the relationships of 32 species of macrobenthos in 21 sites and 11 environmental factors were studied in the offshore water of Rushan Bay. The species - environment biplot was drawn based on the result of CCA, and the relationships between the ecological distribution of the species and communities with the 11 environmental factors were clearly revealed on the biplot. According to the correlation coefficients of the environmental factors with the first two axes, TN, DO, SAL, pH, water depth and TP gradient were found to be the most important environmental factors influencing the ecological distribution of the macrobenthos. 32 species were divided into 6 groups based on the corresponded environmental gradient. 8 species belonged to group Ⅰ were distributed in high TN concentration areas, while group Ⅱ including 4 species was distributed in high DO, SAL and low TN concentration areas. Group Ⅲ including 10 species was distributed in high pH, shallow waters, and 4 species belonged to Group Ⅳ, were found in low pH, deepwater. Only1 species in group Ⅴ was often found in high TP concentration areas, while Group Ⅵ including 5 species, preferred low TP, deepwater. Fig 2, Tab 5, Ref 29