典型喀斯特高原水库浮游植物与环境因子的关系

浮游植物的生长往往受多种环境因素共同作用,独特的地理特征也是影响其密度与群落结构变化的要素之一。为探索喀斯特高原水库浮游植物与环境因子的耦合关系,以贵州省典型喀斯特高原水库——阿哈水库为例,于2019年春(4月)、夏(7月)、秋季(10月)对水库各支流及库中心区域进行采样调查,探究了喀斯特水库基础水环境指标的量级、浮游植物群落组成、优势种变化及其密度的时空分布,进一步揭示浮游植物与环境因子的耦合关系,为喀斯特高原水库浮游植物研究以及水资源保护提供一定的科学依据。结果显示,阿哈水库浮游植物密度在3.95×10⁴-525.35×10⁴cells·L^?1,之间,以蓝藻、硅藻、绿藻、隐藻居多,伪鱼腥藻(Pseudoanabaena sp.)、水华束丝藻(Aphanizomenon flos-aquae)为主要优势种。单因素方差分析(One-way ANOVA)结果表明,浮游植物密度的季节性差异显著(P<0.01),呈夏季>春季>秋季的趋势。由一元线性回归分析可知,在春季,浮游植物密度与溶解氧、pH、钙离子浓度呈极显著线性相关(P<0.01),与透明度、氮磷比具有显著相关关系(P<0.05);然而,浮游植物密度仅与夏季的透明度关系显著(P<0.05),与秋季的所有环境因子均无显著相关关系(P>0.05)。由冗余分析(RDA)可知,影响春季浮游植物群落结构的主要环境因子为pH、钙离子浓度和总磷,夏季为透明度、总磷和氮磷比。秋季浮游植物群落结构可能受低温影响较大。

Relationships between Phytoplankton and Environmental Factors in A Typical Karst Plateau Reservoir

The growth of phytoplankton is often affected by a variety of environmental factors,and unique geographical features are also one of the factors that affect its density and community structure changes.Taking the typical karst plateau reservoir-Aha Reservoir in Guizhou Province of China as an example,the tributaries of the reservoir and reservoir center were sampled in 2019 spring(April),summer(July)and autumn(October).The spatial and temporal distribution of phytoplankton community composition,dominant species and their density in karst reservoir were studied,and the coupling relationship between phytoplankton and environmental factors was further revealed.The results are expected to provide scientific basis for phytoplankton research and water resources protection in karst plateau reservoirs.During the sampling period,the phytoplankton density in Aha Reservoir was 3.95×10⁴-525.35×10⁴ cells·L^?1,among which Cyanophyta,Bacillariophyta,Chlorophyta and Cryptophyta were the most abundant,Pseudoanabaena sp.and Aphanizomenon flos-aquae were the dominant species.One-way ANOVA showed that the seasonal difference of phytoplankton density was significant(P<0.01),summer>spring>autumn.According to the linear regression analysis,in spring,phytoplankton density had a significant linear correlation with dissolved oxygen,pH and calcium ion concentration(P<0.01),and had a significant correlation with transparency and N/P ratio(P<0.05);However,phytoplankton density was only significantly correlated with transparency in summer(P<0.05),but not with all environmental factors in autumn(P>0.05).According to the RDA,the main environmental factors affecting phytoplankton community structure were pH,calcium concentration and total phosphorus in spring,transparency,total phosphorus and N/P ratio in summer.The community structure of phytoplankton may be affected by low temperature in autumn.