山东师范大学学报(自然科学版)

为了解云蒙湖水域特征及浮游植物状况，于2014年8月和10月进行了2次调查采样。结果表明：云蒙湖TN介于0.494～8.215 mg·L^-1;TP介于0.029～0.053 mg·L^-1;Chla为13.65～61.05 mg·L^-1;COD_Mn为6.51～11.08 mg·L^-1;整个库区综合营养状态指数(TLI)较为平均，为57.85～69.69,相差不大。云蒙湖共检出浮游植物8门60种，10月(46种)物种丰富度高于8月(39种),其中绿藻门种类最多，位置组成上为入库口和出库口相对丰富。席藻(Phormidium sp.)、颤藻(Oscilatoria lemmermanni)、鱼腥藻(Anabaena constincta)、针杆藻(Synedra sp.)以及啮噬隐藻(Cryptomonas erosa)为主要优势种群。相关性分析表明：浮游植物密度(D)、香农威纳多样性指数(H)、物种数(S)、均匀度指数(J)与溶解氧(DO)具有显著相关性(P<0.05)。RDA分析表明：NH■-N、Chla及COD_Mn等对浮游植物优势种群的分布及群落结构变化具有较大影响。DO、NH⁺₄-N、Chla是云蒙湖浮游植物种类组成的重要限制因子(P<0.05)。

To investigate the water characteristics and phytoplankton status of Yunmeng Lake, two sampling surveys were conducted in August and October 2014. The results showed that the total nitrogen(TN) ranged from 0.494 mg·L^-1 to 8.215 mg·L^-1, the total phosphorus(TP) ranged from 0.029 mg·L^-1 to 0.053 mg·L^-1, the chlorophyll a(Chla) concentration ranged from 13.65 mg·L^-1 to 61.05 mg·L^-1 and the permanganate index(COD_Mn) ranged from 6.51 mg·L^-1 to 11.08 mg·L^-1in Yunmeng Lake. The comprehensive trophic level index(TLI) of the entire reservoir area was relatively uniform, ranging from 57.85 to 69.69, with little variation. A total of 60 species of phytoplankton belonging to 8 phyla were identified in Yunmeng Lake, with higher species richness in October(46 species) than in August(39 species). Chlorophyta was the most diverse phylum, and the species composition was relatively richer at the inlet and outlet of the reservoir. The dominant species included Phormidium sp., Oscilatoria lemmermanni, Anabaena constincta, Synedra sp. and Cryptomonadaceae erosa. Correlation analysis showed that phytoplankton density( D), Shannon-Wiener diversity index( H ), species number( S) and evenness index( J) were significantly correlated with dissolved oxygen(DO)(P<0.05). Redundancy analysis(RDA) indicated that NH⁺₄-N, Chla, and COD_Mn had significant influences on the distribution of dominant phytoplankton species and changes in community structure. DO, NH⁺₄-N, and Chla were identified as important limiting factors for the phytoplankton species composition in Yunmeng Lake(P<0.05).