洪泽湖大型底栖动物群落结构及其与环境因子的关系

洪泽湖是我国第四大淡水湖,然而关于洪泽湖大型底栖动物的报道较少。为了研究洪泽湖大型底栖动物群落结构特征及其影响因子,在洪泽湖设置20个采样点,进行了为期1周年的季度调查(2010年5月-2011年2月)。共采集到大型底栖动物14种,寡毛类、摇蚊科幼虫和软体动物分别有5种(占总物种数的35.7%)、3种(21.4%)和6种(42.9%)。河蚬为第一优势种(优势度Y=0.18),其次分别为苏氏尾鳃蚓(0.09)、羽摇蚊(0.07)、霍甫水丝蚓(0.06)和铜锈环棱螺(0.06)。群落的平均密度和平均生物量分别为(45.45±7.38)个/m2和(52.43±12.04)g/m2,其中软体动物平均密度和平均生物量最高(24.80±6.20)个/m2和(49.55±11.94)g/m2],摇蚊类次之(13.76±2.87)个/m2和(2.28±0.71)g/m2],寡毛类最低(6.96±2.41)个/m2和(0.60±0.18)g/m2]。全湖Shannon-Wiener、Margalef和Pielou指数分别为2.69、1.10和0.71,各指数季节差异不明显。冗余分析(RDA)结果共解释物种数据累计方差的35.0%;MonteCarlo检验表明,洪泽湖水体中硝酸盐氮、总氮和化学耗氧量是影响底栖动物群落分布最关键的环境因子(F=2.181～3.277,P<0.05)。

Community Structure of Macrozoobenthos and Its Relationship with Environmental Factors in Lake Hongze

Lake Hongze is the fourth largest freshwater lake in China,however,there is limited information on the macrozoobenthos in the lake.Surveys on macrozoobenthos of the lake were carried out seasonally from May 2010 to February 2011,to investigate the community structure and its major driving environmental factors.A total of 14 taxa were identified based on 80 quantitative samples from 20 sampling sites,including oligochaetes(5 species,35.7% of the total),chironomids(3,21.4%) and molluscs(6,42.9%).The dominant species were Corbicula fluminea(dominance Y = 0.18),Limnodrilus hoffmeisteri(0.09),Chironomus plumosus(0.07),Limnodrilus hoffmeisteri(0.06) and Bellamya aeruginosa(0.06),respectively.The average total density and biomass were(45.45 ±7.38) ind/m2 and(52.43 ± 12.04) g/m2 respectively,mainly consisted of oligochaetes (6.96 ± 2.41) and(0.60 ± 0.18) ],chironomids (13.76 ± 2.87) and(2.28 ± 0.71) ]and molluscs (24.80 ± 6.20) and(49.55 ± 11.94) ].The annual values of Shannon-Wiener,Margelef and Pielou’s indices were 2.69,1.10 and 0.71,respectively,without obviously seasonal changes.Among 14 environmental factors,the results of redundancy analysis accounted for 35% of macrozoobenthos community variance,and Monte Carlo’s test showed that nitrate nitrogen,total nitrogen and COD(F = 2.181-3.277,P < 0.05) were the key factors that significantly influenced the distribution and community structure of macrozoobenthos.