| 摘要: |
| 着生藻类是河流生态系统重要的初级生产者，在维持生态系统多样性、能量流动和物质传递中起关键作用。着生藻类对人为干扰和环境变化响应迅速，广泛应用于河流生物多样性监测和水环境质量评价。比较不同河流着生藻类群落结构及其与环境因子的关系，有助于认识河流生物多样性的维持机制。为此，于2021年春季（5—6月）对金沙江上游主要支流色曲、赠曲、欧曲和藏曲的着生藻类多样性及河流环境进行了调查分析。结果显示，38个样点共鉴定出着生藻类3门34属91个分类单元，各采样点种类数均以硅藻门占比最高。各支流着生藻类密度范围为0.002×105~2.43×105 ind./cm2，生物量范围为0.3×10-3~1.56 mg/cm2，各支流着生藻类密度和生物量无显著差异。不同支流优势种存在一定差异，色曲主要优势种为半丰鞘丝藻（Lyngbya semiplema）、眉藻未定种（Calothrix sp.）和微型舟形藻（Navicula minima）和极小桥弯藻（Cymbella perpusilla）等；赠曲主要优势种为半丰鞘丝藻橄榄绿异极藻（Gomphonema olivaceum）、纤细等片藻（Diatoma tenue）、胡斯特桥弯藻（Cymbella hustedtii）和平片针杆藻（Synedra tabulata）等；欧曲主要优势种为胡斯特桥弯藻、谷皮菱形藻（Nitzschia palea）和半丰鞘丝藻、中型脆杆藻（Fragilaria intermedia）和胡斯特桥弯藻（Cymbella hustedtii）等；藏曲主要优势种为半丰鞘丝藻、希罗鞘丝藻（Lyngbya hieronymusii）、半丰鞘丝藻和极小桥弯藻（Cymbella perpusilla）橄榄绿异极藻（Gomphonema olivaceum）等 。冗余分析显示，电导率、pH、河宽和溶解氧是影响金沙江上游着生藻类多样性的主要环境因子，表明环境过滤在金沙江上游着生藻类群落多样性的空间格局中起着一定的作用。本研究为金沙江上游河流生态系统的保护及水质管理提供了基础资料。 |
| 关键词: 水生生物 指示物种 群落结构 河流健康 青藏高原 |
| DOI： |
| 分类号: |
| 基金项目: |
|
| The spatial pattern of periphytic algae communities in the major tributaries of the upper Jinsha River and the environmental drivers |
|
shangkunyu,han yu,gao xin,sun dan dan,jiang hao,lin peng cheng
|
|
Institute of Hydrobiology, Chinese Academy of Sciences
|
| Abstract: |
| Periphytic algae constitute integral components of river ecosystems, serving as a starting point in the food chain of aquatic ecosystems. They play a crucial role in maintaining ecological diversity, energy flow, and material transfer within ecosystems. Benthic algae respond rapidly to anthropogenic disturbances and environmental changes, and are widely used in river biodiversity monitoring and water environment assessment. Comparing the species composition and distribution among periphytic algae communities in different rivers along with elucidating their relationships with riverine environments, contributes to a better understanding of mechanisms maintaining river biodiversity. Therefore, we sampled periphytic algae from 38 sites in the main tributaries of the upper Jinsha River (i.e., Sequ River, Zengqu River, Ouqu River, and Zangqu River) during May and June of 2021, and recorded their environmental condition. The influence of environmental factors on the community structure of periphytic algae was analyzed using a redundancy analysis method. Results revealed 91 taxa of periphytic algae, belonging to 3 phyla and 34 genera, with Bacillariophyta as the most species-rich group. Periphytic algae density in the major tributaries of the upper Jinsha River varied from 0.002×105-2.43×105 ind./cm2 and the biomass varied from 0.3×10-3~1.56 mg/cm2. No significant differences were found in benthic algae density and biomass among the various tributaries. In the Sequ River, dominant species included Lyngbya semiplema, Calothrix sp., and Navicula minima. Within the Zeng River, dominant species included Lyngbya semiplema, Diatoma tenue, and Synedra tabulata. The Ou River exhibited dominant species such as Lyngbya semiplema, Fragilaria intermedia, and Cymbella hustedtii. In the Zang River, the dominant species were Lyngbya semiplema, Lyngbya hieronymusii, and Cymbella perpusilla. Redundancy analysis indicated that conductivity, pH, channel width, and dissolved oxygen were the main driving factors affecting the community structure of the dominant taxa in main tributaries of the upper Jinsha River. These findings suggest that environmental filtering plays a role in the spatial patterns of periphytic algae communities in the upper Jinsha River. This study provides basic data and a theoretical basis for the sustainable management and conservation of aquatic ecosystems in the main tributaries of the upper Jinsha River. |
| Key words: Aquatic organisms indicator species community structure River health the Qinghai-Tibet Plateau |
