鄱阳湖国家级自然保护区浮游生物群落结构及空间分布

COMMUNITY STRUCTURE AND SPATIAL DISTRIBUTION OF PLANKTON IN THE POYANG LAKE NATIONAL NATURE RESERVE, CHINA

为评价春季大旱后鄱阳湖国家级自然保护区浮游生物现状,对保护区所辖8个子湖及赣江和修河部分河段的浮游生物进行调查和分析。调查共发现浮游植物53属97种、浮游动物23属42种(包括原生动物13种、轮虫23种、枝角类3种和桡足类3种),其中大湖池和朱市湖是浮游生物种类数最多的2个子湖。各子湖及赣江和修河间浮游生物现存量差异较大,其变化范围分别为260—(8.18×106)cells/L(浮游植物)、3630—73173 ind./L(浮游动物),赣江以西区域的子湖和修河的浮游生物现存量显著高于赣江及其以东区域的子湖。调查水域优势度值(Y)大于0.02的浮游生物包括蓝藻1种、绿藻2种、硅藻5种、原生动物4种及轮虫5种。浮游生物Shannon-Wiener多样性指数(H′)和均匀度指数(J)的最大值均分别为2.41和0.96,而其丰富度指数(Dm)值均小于3。3种多样性指数综合评价表明,保护区各子湖与修河和赣江水体受污染程度较轻,除蚌湖和梅西湖外,均处于中污状态。

To evaluate the plankton characteristics of the Poyang Lake National Nature Reserve after the drought oc-curred in spring 2011, the community structure and spatial distribution of plankton in the Poyang Lake National Nature Reserve were investigated and analyzed in August, 2011. A total of 97 phytoplankton and 42 zooplankton species were identified, which belonged to 49 and 23 genera, respectively. The zooplankton were consisted of 13 species of protozoa, 23 species of rotifera, 3 species of cladocera and 3 species of copepoda. The numbers of plankton species in Lake Da-huchi and Zhushihu were more than that of the other lakes and rivers. The abundances of plankton among each lake and river were significantly different, and varied from 260 to8.18×106 cells/L for phytoplankton and 3630 to 73173 ind./L for zooplankton, respectively. The results showed that the abundances of plankton in Xiu River and the lakes that lo-cated at the west of Gan River, were significantly higher than that of Gan River and the other lakes. Statistical analysis indicated that the dominant species of phytoplankton in the Poyang Lake National Nature Reserve wereAnabaena flos-aquae, Scenedesmus quadricauda,S.bijuga,Melosira granulatavar. angustissima,M. granulate,M. graunlatavar. angustissima f. spiralis,Synedra acus andFragilaria capucina,while the dominant species of zooplankton wereStentor amethysinus,Difflugia lobostoma,Centropyxis discoides,Strombidim viride,Brachionus diversicornis,B. bennini, Trichocerca rousseleleti,T. longiseta andAsplanchna girodide. The maximum values of diversity indices （H′） and evenness （J） of both phytoplankton and zooplankton were 2.41 and 0.96, respectively. The values of abundance （Dm） of plankton were both less than 3. Evaluated with the diversity indices （H′）, evenness （J） and abundance （Dm） of plankton, the water qualities of lakes and rivers in the Poyang Lake National Nature Reserve wereβ-type of pollution, except Lake Banghu and Meixihu.