莱州湾浮游植物种群动态研究

STUDY ON POPULATION DYNAMICS OF PHYTOPLANKTON IN LAIZHOU BAY

根据 1998年莱州湾浮游植物调查和 1960年、1982年、1992年的调查资料进行了对比研究 ,报道了莱州湾浮游植物的种类组成、数量分布和年间变化规律。调查资料显示 ,莱州湾已鉴定的浮游植物有 2门 31属 80种 ,其中硅藻门占绝对优势有 2 7属 70种 ,其次是甲藻门有 4属 10种。从 1960年到 1998年 ,莱州湾浮游植物的种数呈逐年下降的趋势 ,其中 1998年种数仅有 2 0属 5种。从数量分布来看 ,1982年较 1960年有较大幅度的增长 ,平均个体数量为 12 70 .2万个 / m3,之后则逐年下降 ,到 1998年仅为 1982年的 4 .3%。与此同时 ,莱州湾浮游植物的生物多样性、丰度系数、均匀指数以及种群的相似系数均有逐年下降的趋势 ,优势种类的优势愈来愈明显 。

The species composition, quantity distribution, their seasonal and interannual variation law of phytoplankton in Laizhou Bay were studied comparatively and reported,according to the cruises data in 1960,1982,1992 and 1998. The result showed that, there were 2 phylum 31genera and 80 (mostly warm inshore) species of phytoplankton in the Laizhou Bay, the cells and species of Bacillariophyta (27 genera and 70 species) were absolutely predominant, followed by those of the Ceratium (4 genera and 10 species). The phytoplankton species obviousely reduced from 27 genera and 65 species in 1960 to 20 genera and 45 species in 1998. The peak phytoplankton abundance was observed in 1982, it reached 1270.2×10 4 cells/m 3, and then reduced year after year. The least abundance of phytoplankton was recorded in 1998, which only accounted for 4.3% of those in 1982. It is concluded that the biodiversity, species richness index, evenness and population similar index of phytoplankton in Laizhou Bay have reducing trend year by year. The community structure of the phytoplankton in Laizhou Bay Simplifies year after year, and the dominance of the dominant species is much more obvious.