人民黄河

为了解延河着生藻类群落分布及影响因素,于2023年8月(丰水期)、10月(平水期)及2024年3月(枯水期)对延河及其支流15个监测断面进行采样分析,系统探索该河流着生藻类构成,分析水环境因子与群落结构之间的关系。共检出着生藻类6门67属179种,硅藻门占52.5%,绿藻门占24.0%、蓝藻门占19.6%、裸藻门占2.8%、金藻门和隐藻门均占0.55%;各水期着生藻类物种数表现为丰水期>枯水期>平水期,优势种16属25种(枯水期占84%),主要为硅藻,蓝藻仅在枯水期检出,丰水期未检出优势种;丰、平、枯水期着生藻类平均密度分别为4.5×10⁴、6.8×10⁴、4.2×10⁴个/cm²,平水期平均密度显著高于枯水期和丰水期;Margalef丰富度指数表明延河水质丰水期无污染,平、枯水期均为β-中污染;RDA表明丰、平、枯水期影响着生藻类的共同主要因子为水温、pH值、NH₃-N,此外,水深、TP、流速和TN分别为丰、平、枯水期的主要影响因子。

In order to explore the spatial and temporal distribution of periphytic algal community and its relationship with water environmental factors in Yanhe River basin,a primary tributary of the middle reaches of the Yellow River,Samples were collected from 15 monitoring sections of the Yanhe River Basin from August(high water period),October(normal water period) 2023 and March(low water period) 2024.For the first time,the composition of periphytic algae and the relationship between water environment factors and community were studied.The results indicated that a total of 179 periphytic algae species were identified in Yanhe River Basin,belonging to 67 genera of 6 phyla.The species of Bacillariophyta accounted for 52.5%,the Chlorophyta for 24.0%,the Cyanophyta for 19.6%,the Euglenophyta for 2.8%,the Chrysophyta and Cryptophyta both for 0.55%.The species number of periphytic algae was in the order of high water period>low water period>normal water period.There are 25 dominant species of periphytic algae,belonging to 16 genera,mainly Bacillariophyta,in particular,the low water period constituted for 84%,while Cyanophyta were only detected during the low water period and there were no dominant species in the high water period.The average densities of periphytic algae in the high,normal,and low water periods were 4.5×10⁴ ind/cm²,6.8×10⁴ ind/cm²,and 4.2×10⁴ ind/cm²,respectively,with the autumn density being significantly higher than that spring and summer.The Margalef richness index demonstrated that the water quality of the Yanhe River Basin was no polluted in the high water period,buy the pollution wasβ-medium in both the normal and low water periods.Redundancy analysis(RDA) revealed that the common main water environment factors affecting periphytic algae diversity distribution in Yanhe River Basin during the high,normal and low water periods were water temperature,pH value and ammonia.Additionally,water depth,total phosphorus,flow velocity and total nitrogen were the main influencing factors in the high water period,normal water period and low water period,respectively.Short-term monitoring is insufficient to accurately reflect the enhancement of water ecological quality and the alterations in the aquatic community structure within the basin.