达里诺尔湖浮游植物群落结构及与环境因子的关系

发布时间：2018-11-20 20:10

【摘要】：达里诺尔湖(达里湖)是内蒙古地区第二大淡水湖,也是重要的渔业生产基地。浮游植物是水域环境中重要的初级生产力,是浮游动物和鱼类的饵料。浮游植物群落结构的改变不仅指示了湖泊水质的变化,而且反映流域环境的变化特征。为了揭示达里湖浮游植物群落结构及与环境因子的关系,于2015年7-9月和2016年1月对湖水不同深度进行取样。通过对浮游植物的种类与优势种组成的分析,查明了浮游植物在湖中的时空分布特征,采用相关性分析与典范对应分析的方法,确定了不同环境因子对浮游植物分布特征的影响,选用营养状态指数和浮游植物生态学指标对水体进行了水质营养状态现状评价。主要研究成果如下:(1)共鉴定浮游植物7门、51属、130种(含变形和变种),其中包括优势种3门、19属、31种,绿藻门的湖生卵囊藻(Oocystis lacustristris)和单生卵囊藻(Oocystis solitaria)优势度偏大,优势种组成为绿藻-蓝藻-硅藻型。(2)浮游植物在年内不同月份总种类数变化较大,平均为60种,7月份总种类数最多。在空间上也存在较大的差异,水平分布上,在湖泊西北部靠近岸边的B4点总种类数最多;垂直分布上,水面下0.5m处总种类数最多。浮游植物丰度和生物量,整体上层水体从湖外围到中心呈递减趋势,下层水体从东北向西南递减趋势;垂向随水深呈递减趋势。(3)浮游植物的Shannon-Wiener多样性指数H、Margalef丰富度指数D在水平分布上,湖区北部和湖心区均高于湖区南部;在垂向分布上,水面下1.5m处值最大。Pielou均匀度指数J水平分布较均匀,垂向随水深增大。(4)湖水平均透明度(SD)时空差距较小。电导率(EC)和水温(T)空间变化不大。水体呈碱性,其中1月份较高,同期溶解氧(DO)也较大。盐度(SAT)1月份平均值偏小,7月份在贡格尔河入湖口一带的A7和B6点明显偏小。(5)水体总氮(TN)、总磷(TP)和正磷酸盐(DIP)冬季大于夏秋季,总体空间分布变化显著。溶解性总磷(DTP)冬季小于夏秋季,水平分布较均匀。化学需氧量(CODCr)冬季约为夏季的2.5倍,叶绿素a(Chl-a)8月份平均值最大,样点差距明显。(6)浮游植物丰度与水温(T)、总氮(IN)、总磷(TP)、叶绿素a(Chl-a)、透明度(SD)和溶解氧(DO)呈正相关,与pH值和化学需氧量(CODCr)呈负相关。影响达里湖浮游植物结构特征的主要因素是温度(T)、透明度(SD)、叶绿素a(Chl-a)、化学需氧量(CODCr)和盐度(SAT)。水体营养状态处于中-富营养水平,呈轻-中度污染状态。
[Abstract]:Dalinole Lake is the second largest freshwater lake in Inner Mongolia and an important fishery production base. Phytoplankton is an important primary productivity in water environment, and is the feed of zooplankton and fish. The change of phytoplankton community structure not only indicates the change of lake water quality, but also reflects the changing characteristics of watershed environment. In order to reveal the structure of phytoplankton community and the relationship between phytoplankton community and environmental factors, samples were taken from July to September 2015 and January 2016. Based on the analysis of phytoplankton species and dominant species composition, the spatial and temporal distribution characteristics of phytoplankton in lake were found out, and the correlation analysis and canonical correspondence analysis were used. The effects of different environmental factors on the distribution characteristics of phytoplankton were determined. The nutrient status index and phytoplankton ecological index were used to evaluate the present status of water quality nutrition. The main results are as follows: (1) A total of 130 species of phytoplankton, including 7 phyla, 51 genera, 130 species, including 3 dominant species, 19 genera, 31 species, were identified. The dominance of (Oocystis lacustristris) and (Oocystis solitaria) of Chlorophyta is larger, and the dominant species is Chlorophyta-cyanobacteria-diatom type. (2) the total species number of phytoplankton varies greatly in different months of this year, with an average of 60 species. July saw the largest total number of species. In the horizontal distribution, the total number of B4 species near the shore of the northwestern lake is the largest, and the total species number is the most at 0.5 m below the water surface in the vertical distribution. The abundance and biomass of phytoplankton decreased from the periphery to the center of the lake in the upper layer and from northeast to southwest in the lower layer. (3) the Shannon-Wiener diversity index of phytoplankton was higher than that in the southern part of the lake area in the horizontal distribution. In the vertical distribution, the maximum value is at 1.5m below the water surface. The horizontal distribution of Pielou evenness index J is more uniform, and the vertical distribution increases with the depth of water. (4) the temporal and spatial difference of average transparency (SD) of lake water is smaller. The spatial variation of conductivity (EC) and water temperature (T) is not obvious. The alkalinity of the water was higher in January, and the (DO) of dissolved oxygen was larger in the same period. The average value of salinity (SAT) in January was smaller than that at A7 and B6 in July at the mouth of Gongger River. (5) Total nitrogen (TN), total phosphorus (TP) and orthophosphate (DIP) in winter were larger than those in summer and autumn. The total spatial distribution changed significantly. The dissolved total phosphorus (DTP) in winter is smaller than that in summer and autumn, and the horizontal distribution is more uniform. The chemical oxygen demand (CODCr) in winter is about 2.5 times of that in summer, and the average value of chlorophyll a (Chl-a) in August is the largest, and the difference between the samples is obvious. (6) phytoplankton abundance and water temperature (T), total nitrogen (IN), total phosphorus (TP),. Chlorophyll a (Chl-a), transparent (SD) and dissolved oxygen (DO) were positively correlated, and negatively correlated with pH and (CODCr). The main factors affecting phytoplankton structure in Lake Daly are temperature (T), transparency (SD), chlorophyll a (Chl-a), chemical oxygen demand (CODCr) and salinity (SAT). The nutrient state of water was medium-eutrophication level and light-medium pollution state.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X524;X173

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