辽东湾北部海域大型底栖动物研究：Ⅱ.生物多样性与群落结构

Studies on Macrobenthos in the Northern Waters of Liaodong Bay:Ⅱ.Biodiversity and Community Structure

为深入了解辽东湾北部海域大型底栖动物的生态学特征及其与环境因子的相互作用,依据2007年7月下旬在辽东湾进行的大型底栖动物生态调查数据,论述了大型底栖动物的生物多样性与群落结构特点.调查区内大型底栖动物的Shannon-Wiener多样性指数为0-3.40,平均值为2.41;Margalef物种丰富度指数为0-2.40,平均值为1.58.两指数的空间分布趋势较为一致,低值区主要位于调查区北部的沿岸浅水区,其他海域的生物多样性指数较高且无显著的空间差异.以20%的相似性程度划分,取样站可被划为7个大型底栖动物站组,各站组在调查区内呈斑块状分布.其中,有4个站组（站组Ⅰ,Ⅱ,Ⅴ和Ⅵ）的生物量曲线始终在丰度曲线之上,且优势度明显,表明大型底栖动物群落尚未受到显著干扰;其他站组的生物量曲线与丰度曲线相互交叉或非常接近,显示大型底栖动物群落已受到中等程度干扰.统计分析表明,水深,底层水中的ρ（DO）,ρ（总磷）共同构成了解释调查区内大型底栖动物群落结构的最佳环境因子组合,它们与栖息密度（R=0.484）和生物量（R=0.489）的相关关系均达到显著水平（P〈0.01）.

On the basis of the ecological survey conducted in July, 2007 in the northern waters of Liaodong Bay, the biodiversity and community structure of macrobenthos were studied using the multivariate an.alysis method to assess the ecological characteristics of macrobenthos and its relationships with environmental factors. The Shannon-Wiener index of macrobenthos in the survey area was 0-3.40, with average value 2.41; the corresponding Margalef＇ s richness index was 0-2.40, with average value 1.58. These two biodiversity indices showed similar distribution patterns in the northern waters of Liaodong Bay, with low values mainly located in the northern adlittoral area, while the indices in other areas were relatively high and showed little spatial differences. A total of seven macrobenthic groups were split out from these sampling stations for 20% similarity, exhibiting a nested distribution pattern in the survey area. There were four station groups whose biomass curves were above the abundance curves, indicating that the communities were not disturbed significantly. However, the biomass curves of the other station groups were very close to or intersected with the bundance curves, indicating that the communities were moderately disturbed. The combination of water depth, dissolved oxygen and total P content in the bottom waters produced the best match of all the environmental factors to macrobenthic assemblages; the relationship coefficients with abundance （ R = 0.484） and biomass （ R = 0.489） were all up to the significant level （P〈0.01）.