拉萨河中上游原生动物群落结构特征及其与水环境之间的关系

发布时间：2018-01-05 17:30

本文关键词：拉萨河中上游原生动物群落结构特征及其与水环境之间的关系　出处：《西藏大学》2017年硕士论文　论文类型：学位论文

【摘要】：为了研究西藏地区拉萨河中上游原生动物多样性及其与水环境之间的关系,2015年5月至2016年12月期间,在拉萨河中上游设置8个样点,利用25号浮游网分三个季节(春、夏、秋)进行了6次数据采集,共采集到水样96个,用活体镜检和固定染色相结合的方法鉴定物种,直接计数法统计数量。利用各类群落参数、相似性及相关性对拉萨河中上游原生动物群落结构及其与水环境之间的关系进行分析,结果如下:(1)拉萨河中上游共鉴定原生动物148种,其中春季共鉴定出原生动物74种,隶属于2门5纲18目31科40属;夏季共鉴定出原生动物73种,隶属于2门6纲15目24科34属;秋季共鉴定出原生动物83种,隶属于2门4纲17目27科35属。三个季节中,无论在优势种还是所有物种中,纤毛虫均占有优势。(2)拉萨河中上游原生动物多样性指数较低(2.73),夏季(2.98)秋季(2.70)春季(2.49);丰富度指数较低(2.34),秋季(2.55)夏季(2.26)春季(2.23);均匀度指数较高(0.83),秋季(0.91)春季(0.81)夏季(0.78);优势度指数较低(0.16),夏季(0.23)春季(0.17)秋季(0.10);污生指数较高(2.91),夏季(3.13)春季(2.84)秋季(2.77);这表明,拉萨河中上游原生动物物种多样性较低,物种分布均匀,优势度不明显,水质状况良好。(3)拉萨河中上游原生动物营养功能类群,三个季节均符合从上游到中游BS类群逐渐增多,PA类群逐渐降低的趋势,这符合外源营养物质与功能类群的变化趋势。(4)拉萨河中上游各样点相似性系数较低,三个季节均为极不相似,表明各样点具有显著的时空差异性。(5)对拉萨河中上游原生动物群落特征参数及水环境进行Pearson二元变量相关性分析,结果显示,春季影响拉萨河中上游原生动物群落结构的主要理化因子为浊度和溶解氧,夏季主要影响因子为pH和溶解氧,秋季主要影响因子为浊度和氨氮。(6)结合生物参数和水体理化因子对拉萨河中上游水环境进行评价,结果显示,拉萨河中上游三个季节水质均处于轻污染或清洁(Os),春季除S5样点为轻污染外,其他样点均为清洁;夏季除S3样点为轻污染外,其他样点均为清洁;秋季各样点均为清洁。这表明拉萨河整体水质状况良好,水环境稳定。
[Abstract]:In order to study the diversity of protozoa in the middle and upper reaches of Lhasa River in Tibet and its relationship with the water environment, eight samples were set up in the upper and middle reaches of the Lhasa River from May 2015 to December 2016. A total of 96 water samples were collected in three seasons (spring, summer and autumn) using 25 floating net. The species were identified by the method of in vivo microscopic examination and fixed staining. The relationship between the community structure and the water environment in the upper and middle reaches of Lhasa River was analyzed by using various community parameters, similarity and correlation. The results were as follows: 1) 148 species of protozoa were identified in the upper and middle reaches of Lhasa River, of which 74 species were identified in spring, belonging to 2 phyla, 5 classes, 18 orders, 31 families and 40 genera. In summer, 73 species of protozoa were identified, belonging to 2 phyla, 6 classes, 15 orders, 24 families and 34 genera. In autumn, 83 species of protozoa were identified, belonging to 2 phyla, 4 classes, 17 orders, 27 families and 35 genera. Ciliates are dominant. (2) Protozoan diversity index in upper and middle reaches of Lhasa River is lower than that in summer, 2.98) in autumn, 2.70) in spring. The richness index is lower (2.34) and 2.55 (autumn) and 2.26 (spring). The evenness index was higher than that in autumn (0.83), and in autumn (0.91)) in spring (0.81)) in summer (0.78); The dominance index is lower (0.16) and 0.23 (in summer) and 0.17 (in spring) than in autumn (0.10); The pollution index was higher (2.91g, 3.13 in summer) and 2.84 (in spring) than that in autumn (2.77); This indicates that the species diversity of protozoa in the upper and middle reaches of Lhasa River is low, the species distribution is uniform, the dominance is not obvious, and the water quality is good. 3) the nutrient functional group of protozoa in the middle and upper reaches of Lhasa River. The three seasons were consistent with the increasing of BS group from upstream to middle reaches and the decreasing trend of PA group. This is in line with the trend of exogenous nutrients and functional groups. 4) the similarity coefficient of various points in the upper and middle reaches of Lhasa River is low and the three seasons are very different. The results showed that there were significant spatial and temporal differences in various points. (5) the correlation analysis of the characteristic parameters of protozoa community and the water environment in the upper and middle reaches of Lhasa River by Pearson binary variables was carried out. The main physical and chemical factors affecting protozoa community structure in the upper and middle reaches of Lhasa River were turbidity and dissolved oxygen in spring, pH and dissolved oxygen in summer. In autumn, the main influencing factors were turbidity and ammonia nitrogen. 6) combined with biological parameters and physical and chemical factors of water body to evaluate the water environment in the upper and middle reaches of Lhasa River. In the three seasons of Lhasa River, the water quality was light polluted or cleaned. Except for S5 sample, the other samples were clean in spring. In summer, all the samples were clean except for the light pollution in S3 samples. The results showed that the whole water quality of Lhasa River was good and the water environment was stable.
【学位授予单位】：西藏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q958

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