【作者】 郭云；

【导师】 支崇远；

【作者基本信息】 贵州师范大学 ， 植物学， 2008， 硕士

【摘要】 硅藻对水体环境因子的变化反应非常敏感性,被应用于水质监测和评价中。欧美国家一些水环境管理机构已经将硅藻应用于河流、湖泊水质的评价,而国内尚未建立河流水质生物监测体系――硅藻监测体系。要建立硅藻监测体系,首先要研究硅藻与环境因子间的关系。目前对喀斯特地区河流硅藻与环境因子的研究报道甚少,对乌江底栖硅藻的定量研究,至今尚未见报道。本文对喀斯特发育典型的乌江中上游15个采样点的枯水期和丰水期开展底栖硅藻与水环境因子关系的定量研究。对各采样点的底栖硅藻丰度、相对丰度、优势种、属种分布、群落构成进行定量分析。现场测定了水温（WT）、流速（V）、氧化还原点位（ORP）、溶解氧（DO）、电导率（COND）和pH 6项物理指标,实验室内分析了浊度（Turb）、化学需氧量COD、总磷TP、总氮TN、可溶性二氧化硅（SiO₂）,K⁺、Na⁺、Mg²⁺、Ca²⁺、HCO₃^-、Cl^-、SO₄^2-、NO₃^- 8种离子和铜（Cu）、铅（Pb）、镉（Cd）、砷（As）、汞（Hg）5种元素等理化指标。通过相关分析、方差分析、聚类分析、主成分分析和加权平均回归分析等方法,分别对底栖硅藻和水体11个理化因子、8种离子及重金属元素之间的关系进行数理统计分析,提取不同营养物质的底栖硅藻指示种,并建立两个不同时期底栖硅藻属种、丰度和水体理化因子间的函数方程。研究结果发现:（1）N. dissipata （Kütz.） Grun.等8个底栖硅藻种的TP最佳值均在100ug/L以上,表明它们可能是乌江中上游富营养化发生的指示性属种。Diatoma、Fragilaria、Synedra、Achnanthes这四个属的TP生态最佳值为50ug/L—70ug/L间,它们可能是乌江中上游TP低浓度指示种。（2）HCO3-是影响枯水期底栖硅藻属种分布第一显著因子,其次是SO₄^2-和K⁺。Gomphonema gracile var. intricatiforma Mayer等13个种的HCO₃^-最佳值在108mg/L—123mg/L间,这些底栖硅藻可能作为HCO3-含量较高水体的指示性物种。（3）TP是影响枯水期底栖硅藻属种分布的第一显著性因子,TN、COD和COND对枯水期底栖硅藻属种分布的影响也十分重要。（4）TP也是影响枯水期底栖硅藻丰度的第一显著因子（R=0.682,P<0.01）,TN、COD、COND、pH、Turb、SiO2和DO对底栖硅藻丰度也有重要影响（R=0.674,R=0.666,R=0.597,R=0.621,R=0.548,R=0.572,R=-0.526）。TP与枯水期底栖硅藻丰度间的线性回归方程:Y=8926+4291X（P<0.01）。（5）8种离子中,Ca²⁺是影响枯水期底栖硅藻丰度的第一主导因子（R=0.893,P<0.01）,其次是SO₄^2-和HCO₃^-（R=0.584,R=0.640,P<0.05）。Ca²⁺与枯水期底栖硅藻丰度间的线性回归方程: Y=-242.44+183.81X（P<0.01）。（6） V是影响丰水期底栖硅藻丰度的第一显著因子（R=0.749,P<0.01）,COND、COD和TP对底栖硅藻的影响也显著（R=0.526, R=0.563, R=0.629, P<0.05 ）。丰水期底栖硅藻丰度和V间的Logarithmic对数函数:y=9702.75+2793.17ln（t）（P<0.01）。（7）8种离子核5种重金属元素中,Hg元素是影响丰水期底栖硅藻丰度的第一显著因子（R=0.808,P<0.01）。其次是K⁺、Cl^-、和HCO₃^-。丰水期底栖硅藻丰度和Hg元素之间的Compound指数方程:y=8836.75×2.58418t（P<0.01）。（8）在乌江中上游枯水期和丰水期共发现底栖硅藻种（包括变种及变型）239个,乌江硅藻物种多样性仍然保持较好水平。丰水期底栖硅藻生物多样性比枯水期低,两时期的普生种均为舟形藻属（Navicula）、桥弯藻属（Cymbella）和异极藻属（Gomphonema）。各样点的底栖硅藻优势种不同。研究结果为乌江流域乃至喀斯特硅藻植物区系特征提供科学依据,为建立用硅藻监测和评价水质的生物体系提供理论基础。更多还原

【Abstract】 Diatoms are used for monitoring and evaluating the quality of river water. Some European countries have evaluated the quality of rivers and lakes water by diatoms. But now in China, the biological monitoring system of diatom has not been built. In order to built the system, we should study on the relationship between diatoms and physcicochemical factors. The quantitative investigation of the benthic diatoms in the middle and upper of Wujiang River has not been reported yet, as well as the relationship between diatoms and physcicochemical factors.In the drought and peak periods, Benthic diatoms of the 15 sample points were collected and identified. The aboundance, relative aboundance and dominant sociales of diatom were analyzed quantitativly. WT, ORP, DO, COD, COND, pH, anions, cations and heavy metals were measured. The relationship between the benthic diatoms and the physcicochemical factors were analyzed by Principal Component Analysis, Cluster Analysis and Correlation Analysis. At the last, the diatom-enviromental factors transfer functions were established.The main conclusions were summarized as following:（1） The Tp optima of Navicula. ontana Krasske and other 7 benthic diatoms were above 100ug/L, which may be indicators of the outbreak of eutrophication in the middle and upper of Wujiang River. The Tp optima of Diatoma、Fragilaria、Synedra and Achnanthes were 50mg/L—70mg/L,which may be indicators of rivers of less contain of Tp.（2） HCO₃^-, SO₄^2-, K⁺ were the most prominent factors which affected the distribution of the bnethic diatom in the drought period. HCO₃^- was the first factor. The HCO₃^- optima of Gomphhonema affine Kütz. and other 12 benthic diatoms were 108mg/L—123mg/L, which may be indicators of rivers of more contain of HCO₃^-. （3） TP was the most important factor which affected the distribution of the benthic diatom in the drought period, then TN, COD, COND.（4） TP was the most important factor which affected the abundance of benthic diatom in the drought period（R=0.682,P<0.01）. TN、COD、COND、pH、Turb、SiO₂ and DO were also the important factors（R=0.674,R=0.666,R=0.597,R=0.621,R=0.548,R=0.572,R=-0.526）.The equation of TP and the abundance of benthic diatom was Y=8926+4291X（P<0.01）.（5） In 8 kinds of ions, Ca2+ was the most important factor which affected the abundance of benthic diatom in the drought period （R=0.893,P<0.01）, then SO₄^2- and HCO3-（R=0.584,R=0.640,P<0.05）. The line regression equation of Ca²⁺ and the benthic abundance of diatom was Y=-242.44+183.81X（P<0.01）.（6） V was the first factor which affected the abundance of the benthic diatom in the peak period（R=0.749,P<0.01）, COND, COD and TP were also very important factors（R=0.526, R=0.563, R=0.629, P<0.05）。The Logarithmic equation of V and the benthic abundance of diatom was y=9702.75+2793.17ln（t） （P<0.01）.（7） In 8 kinds of ions, Hg was the first dominant factor which affected the abundance of the benthic diatom in the peak period（R=0.808,P<0.01）, and The Compound equation was y=8836.75×2.58418t（P<0.01）.（8） Totally 239 species （including varieties） were identified in the drought and peak period. The multiplicity of benthic diatom in the peak period was less than in the drought period. Navicula was dominant in both the two periods. The dominant sociales of the every sample point in the two periods were different, the common species were similar.The conclusions will support scientific foundation for studying the character of Wujiang River, monitoring and estimating water quality and setting up diatom monitoring system.更多还原