Department of Biology, Faculty of Art and Science, Gaziantep University, Gaziantep, Turkey.
Department of Biology, Faculty of Science, Herat University, Herat, Afghanistan.
Environ Sci Pollut Res Int. 2024 Sep;31(42):54463-54480. doi: 10.1007/s11356-024-34765-x. Epub 2024 Aug 28.
It is essential to determine the dominant/indicator species and their ecological preferences to develop a comprehensive bioassessment strategy for rivers. The objective of this work was to provide dependable ecological evaluation techniques for ecosystems that experience significant human-induced disruptions, with the Hari Rud River (a transboundary water resource) serving as a case study during the May (wet) and July (dry) periods of 2023. Canonical correspondence analysis revealed that electrical conductivity (EC), dissolved oxygen, ortho-phosphate (P ), and nitrate (N ) had substantial impacts on the spatial distribution of diatom species in the basin. Relatively pollution-tolerant species, including Nitzschia brevissima, N. capitellata, N. umbonata, N. palea, N. dissipata, and Navicula cryptocephala, had close relationships with EC and P , integrated with Joi Injil and Karbar streams. Of the sampling stations, especially Hari Rud River1 and Hari Rud River2, exhibited pollution-sensitive diatom species, Cymbella excisa, Achnanthidium minutissimum, Diatoma moniliformis, Cymbella affinis, and Meridion circulare. Various eco-regional diatom metrics exhibited distinct scores, indicating a range of ecological status from high to bad in the Lower Hari Rud River basin. European diatom indices revealed good ecological status for Hari Rud River 1 and 4, but poor or bad ecological statuses for Joi Injil and Karbar streams. The findings of the current study emphasize the requirements of autecological studies to understand the regional diatom compositions and their ideal survival ranges in different locations before considering using non-regional diatom indices to evaluate the ecological status of lotic systems.
确定优势/指示物种及其生态偏好对于制定河流综合生物评估策略至关重要。本研究的目的是为受到人类活动强烈干扰的生态系统提供可靠的生态评估技术，以 2023 年 5 月（湿季）和 7 月（干季）的哈里鲁德河（跨界水资源）为例。典范对应分析表明，电导率（EC）、溶解氧、正磷酸盐（P ）和硝酸盐（N ）对流域中硅藻物种的空间分布有很大影响。相对耐污染的物种，包括短双菱藻、头状双菱藻、弯形双菱藻、苍白双菱藻、散生双菱藻和隐头舟形藻，与 EC 和 P 密切相关，与 Joi Injil 和 Karbar 溪流结合。在采样站中，特别是哈里鲁德河 1 号和哈里鲁德河 2 号，表现出对硅藻物种敏感的污染，包括纤细曲壳藻、微小曲壳藻、单缝舟形藻、相似双菱藻和环面舟形藻。各种生态区域硅藻指标得分不同，表明下哈里鲁德河流域的生态状况从高到差不等。欧洲硅藻指数显示哈里鲁德河 1 号和 4 号具有良好的生态状况，但 Joi Injil 和 Karbar 溪流的生态状况较差或很差。本研究的结果强调了在考虑使用非区域硅藻指数评估流水系统的生态状况之前，需要进行自生态研究以了解区域硅藻组成及其在不同地点的理想生存范围。
