摘要:
对巢湖浮游植物在22个样点,四季采样,进行了种类组成、种群数量、优势种、污染指示种,多样性指数及硅藻指数等群落生态学的初步研究。选用其中种群数量、优势种、污染指示种、硅藻指数对巢湖水质污染及营养水平进行了总评与分区评价。就巢湖总体而论,藻量年均值达111×106个/升(细胞数,或个体数为14.7×106个/升),硅藻指数96.7,群落组成种类中,污染指示种占64.2%,除冬季外,各样点多以微囊藻、鱼腥藻为主的蓝藻占优势,其分布频度年平均达98.8%,多度年平均达79.7%,而在夏、秋季,两者则分别为100和99.7%,表明巢湖已受到中等程度的污染,属蓝藻型富营养湖泊;与过去巢湖浮游植物的调查资料对比,表明最近几年来,人为富营养化进程在加速。
Abstract:
The seasonal ecological features of phytoplankton community including its species composition, population size, dominant species, saprobic indicator, diversity index and diatom biotic index were preliminarily studied at 22 sampling stations in the Chaohu Lake, Anhui Province. By using population densities (individuals and cells per litre), dominant species, saprobic indicators and diatom biotic indices as the important biological parameters for monitoring and evaluating pollution conditions of water quality, the trophic level and saprobic degree of the lake were evaluated in whole and in subareas respectively.Dealing with the Chaohu Lake as a whole, the annual mean density of phytoplankton reached 14.7 ?106 per litre for individuals or 111 ?106 per litre for cells. The diatom biotic index was 96.7 and the saprobic indicators comprised 64.2% of total species in the community. Except in winter when Cyclotella comta had higher frequency and greater abundance the dominant species of planktonic algae were almost entirely consisting of blue-green algae especially Microcystis (M. aeruginosa and M. flos-aquae) and Anabaena. Their frequency attained 98.8%, and abundance, 79.7%, when all seasons were taken into account. In suumer and autumn, the frequency was up to 100%, and the abundance, 99.7%. All these indicate that the lake has suffered from moderate pollution and it might be regarded as a blue-green algae-eutrophic lake.
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