察汗淖尔碱湖浮游植物群落结构与环境因子变化特征及关系

Relationship between phytoplankton community structure and variation characteristics of environmental factors in Chaganore Lake

以内蒙古鄂尔多斯市鄂托克旗乌兰镇的察汗淖尔湖为研究对象,在2017—2018年每年进行4次(4,6,8及10月)采样调查,同时对19项水环境指标进行测定.研究了不同季节中湖水理化因子及浮游植物群落结构的变化,分析了湖水环境变化与浮游植物群落结构变化之间的关系.结果显示:察汗淖尔湖共鉴定出浮游植物4门11属,其中蓝藻门的螺旋藻属(Spirulina)、颤藻属(Oscillatoria)和色球藻属(Chroococcoid);绿藻门的衣藻属(Chlamydomonass)、栅藻属(Scenedesmus)、鼓藻属(Cosmarium)和小球藻属(Chlorella);硅藻门的针杆藻属(Synedra)和舟形藻属(Navicula);裸藻门的囊裸藻属(Trachelomonas)和双鞭藻属(Eutreptia);4月浮游植物种类及生物量最多,10月最少;4~10月,湖水中浮游植物的物种数逐渐增多,但浮游植物的生物量呈下降趋势,优势种为衣藻(Chlamydomonass)和螺旋藻(Spirulina);浮游植物生物量变化范围为0.030~8.357 mg/L,浮游植物Shannon-Wiener指数均值波动范围为0.061~1.132,Pieiou均匀度指数最低值为4月的0.040,最高值为10月的1.00;湖水离子浓度在4~10月逐渐上升,但总磷(TP)、总氮(TN)、铵态氮(NH_(4)-N)和硝态氮(NO_(3)-N)季节性差异不显著;Na^(+),Cl^(-),SO2-4和CO^(2-)_(3)离子浓度在10月份显著升高;根据RAD分析结果,对察汗淖尔湖浮游植物群落组成与分布影响最大的因素为DO,Cl^(-),WT,pH,Na^(+),K^(+)、氮源(NO_(3)-N、NH_(4)-N及TN)及CO^(2-)_(3)+HCO^(-)_(3),其中DO,Cl^(-)和WT为显著性影响因素.

Chaganore Lake located in Wulan Town,Ordos City of Inner Mongolia Region was selected as the research site,sampling surveys were conducted 4 times every year(April,June,August and October)from 2017 to 2018,and 19 water environment indicators were measured simultaneously.The changes in physical and chemical factors of the lake water and phytoplankton community structure in different month were studied,and the relationship between the changes of environment and phytoplankton community structure was analyzed.The results showed that there were 4 phyla and 11 genera of phytoplankton identified in Chaganore Lake,including Spirulina,0scillatoria and Chroococcoid of Cyanobacteria;the genera of Chlamydomonass,Scenedesmus,Cosmarium and Chlorella in Chlorophyta;Trachelomonas and Eugenia belong to the Phylum Diatoms.The biomass and the number of phytoplankton species were the highest in April and the lowest in October;the biomass decreased and the number of phytoplankton species increased in Chaganore Lake with the increase of temperature(WT)from April to October,Chlamydomonass and Spirulina were the dominant species;the variation range of phytoplankton biomass was 0.03~8.357 mg/L,the value of phytoplankton Shannon-Wiener index fluctuated from 0.061 to 1.132,the lowest value of Pieiou evenness index was 0.040 in April,and the highest value was 1.00 in October;there was no significant seasonal difference in total phosphorus(TP),total nitrogen(TN),ammonium nitrogen(NH_(4)-N)and nitrate nitrogen(NO_(3)-N);the ion concentration was gradually increased from April to October,and the concentration of Na^(+),Cl^(-),SO^(2-)_(3) and CO^(2-)_(3) increased significantly in October(P<0.05);RAD analysis showed that DO,Cl^(-),WT pH,Na^(+),K^(+),nitrogen source(NO_(3)-N,NH_(4)-N and TN)and CO^(2-)_(3)+HCO^(-)_(3) were the main environmental factors driving the distribution of phytoplankton community structure in Chaganore Lake,among which,DO,Cl^(-)and WT are significant influencing factors.