芜湖市镜湖轮虫群落结构分析及水质的生态学评价

ANALYSIS OF COMMUNITY STRUCTURE OF ROTIFERA AND ECOLOGICAL ASSESSMENT OF WATER QUALITY IN LAKE JINGHU,WUHU CITY

2003年1—12月,对芜湖市镜湖轮虫群落结构的周年动态进行了研究,并分析了轮虫密度与有关生态因子间的关系。经鉴定,共发现轮虫55种,隶属于15科21属。密度优势种为裂痕龟纹轮虫(Anuraeopsis fissa)、暗小异尾轮虫(Trichocerca pusilla)、前额犀轮虫(Rhinoglena frontalis)、红多肢轮虫(Polyarthra remata)、长三肢轮虫(Filinia longise-ta)、广布多肢轮虫(Polyarthra vulgaris)和多须伪前翼轮虫(Proalides tentaculates),而生物量优势种为前节晶囊轮虫(Asplanchna priodonta)、多须伪前翼轮虫和暗小异尾轮虫。全年轮虫的总密度与水温、叶绿素a浓度及小型纤毛虫密度具有显著的相关性;温度对全年轮虫总密度的影响最大,叶绿素a浓度对春、冬季轮虫总密度影响最大,小型纤毛虫密度对夏季轮虫总密度影响最大,而水温是影响秋季轮虫总密度的主要因素。根据污染指示生物、物种多样性指数和Q值并结合水理化性质对治理后的镜湖水质所进行的初步评价表明,经清淤、截流和换水等措施治理后,小湖区应偏属寡污-β中污至β中污型水体,大湖区属于β中污型水体;目前镜湖水体处于中营养后期—富营养化初期阶段。

The annual dynamics of rotifer community structrue in Lake Jinghu in Wuhu city in 2003 was studied and the water quality was ecologically assessed .The relationships between the rotifer density and the main ecological factors including water temperature,pH,and the densities of small Ciliates, Cladocera and Copepoda were also regressively analyzed.55 species of rotifers were identified,which belong to 15 families and 21 genera. The dominant species determined according to annual average denstity and biomass included Anuraeopsis fissa , Trichocerca pusiUa , Rhinoglena frontalis , Polyarthra remata , Filinia longiseta , Polyarthra vulgaris , Proalides tentaculates , Asplanchna priodonta, Proalides tentaculates and Trichocerca pusiUa. The total density of rotifer was positively correlated with water temperature （w）, Chl-α concentration （e）and small Ciliates density（x）（multiple-linear regression, R2 = 0.38, P 〈 0.05） ,and water temperature had the greatest effect on the total density of rotifers （Standard partial regression index, βv = 0. 684,βc = -0.246, βx = 0.422）. In spring and winter, Chl-α concentration had the greatest effect on the total density of rotifers （βw1 = 0.983,βc1 = -0.683 ;βc2 = -0.631, βx2 = 0.566）. But the total density of rotifers was not positively associated with neither the small Ciliates density or the water temperature. While in summer and autumn, the density of Ciliates and water temperature had the greatest effect on the total density of rotifers,respectively （βw1= -0.225,βc1= -0.154,βc1 = 0.871 ;βx1 = 0.642, βw2= 0.423,βx2 = -0.583）. By means of three biological standards （Qs/T,Shannon-weiner diversity index and Wlllams index, indicator organisms of rotifer species）combined with Physico-Chemical quality of water, the small region of take Jinghu（Station Ⅰ）could be regarded as transition stage from oligo-β mesosaprobity to β mesosaprobity, while the big region（Station Ⅱ）could be considered as β mesosaprobity. The lake might be a meso-eutrophie lake.Although some methods ineluding removing the bottom mud, intercepting the polluted water flowing into the lake and the water exchange have been taken,the improvement of the water quality in lake Jinghu was not significant. It is necessary to adopt more methods including the bio-manipulation to restore lake Jinghu＂as dear as a mirror＂.