渤海鱼类群落生物量指标时空格局的因子分析

渤海鱼类群落个体数指标时空格局的因子分析(朱鑫华,1996;朱鑫华等,1996)表明,在个体数量占优势的群落内,同一月份总鱼种数与第一主成分代表鱼种数成正相关。然而,由于鱼类群落内不同种间个体大小差异悬殊,加上同一鱼种的不同生活史阶段个体重量生长速率变化,导致群落个体数量特征分析多强调了小型种间的相互作用关系,而忽视了大型种,尤其是产卵群体的补充作用(Laevastu and Larkins,1981; Margalef,1979)。本文以生物量指标为目标变量,运用多元统计分析中的因子分析法,解析渤海鱼类群落指标一鱼种生物量生态密度(BED)时空分布格局,主要探讨群落结构时空格局易变性和稳定性,并以相隔10年的季度月资料比较分析,研究生态系统内群落演替动态过程间的相互关系(Ulanowicz and Platt,1985)。

STUDY ON SPATIOTEMPORAL PATTERNS OF FISH COMMUNITY IN BOHAI SEA USING FACTOR ANALYSIS OF BIOMASS INDICATORS

Using factor analysis on quantitative data collected monthly from 1982 to 1985 and seasonal 1992 to 1995 surreys in the Bohai Sea revealed the spatiotemporal patterns of the fish community there. As increasing in species for specific month, number of principal representative components (PRCs )were significantly positively related under cumulated variation for eigenvalues more than 80%(r=0. 9051, df=10, p<0. 001). Seasonal dynamics of species alternation showed that the community was dominated by both warm-temperate and warm water faunistic PRCs which occurred only once the annually.Spatially, stations 19, 20 and 25 in the Bohai Strait ware the most abundant during the cold months (December through April) and from September and October. In other months, the biomass of PRCs was # negatively dependent to the isobath in Liaodong Bay and Laizhou Bay. Station assemblages were overlapped throughout half as the whole Bohai Sea in colder season and more than 1/3 of the Bohai Sea in warmer one. The resulting spatial structures of biomass were due to the fact that many former dominants disappeared because of natural degradation of the ecosystem and anthropogenic impacts on the biological community. The more equal distribution of fewer PRCs, at present, resulted in fewer dominants in the community succession, wider ecological niche, and nearly unique spatial structuring of low biomass.