雅砻江干流着生藻类群落特征及生态位分析

Characteristics and niche analysis of periphyton communities in mainstream of Yalong River

摘要

【目的】为调查雅砻江干流全流域着生藻类的群落现状及其在雅砻江不同江段中的群落差异，【方法】基于2023年5月对雅砻江干流29个断面着生藻类的采样调查，结合生境评价分析不同江段着生藻类群落结构特征变化及优势种生态位，并利用RDA以及Pearson相关性分析优势种对环境因子的响应。【结果】结果显示：共采集到着生藻类96种，硅藻门占比89.6%;上游江段着生藻类种类数共7种，细胞密度平均为4 296.3 cells/cm²,优势物种优势度平均，优势物种生态位宽度在1.35~2.05之间，生态位重叠程度为0.628,显著优于中下游生境较好江段和中下游生境较差江段，表明上游江段因未受建坝影响，其着生藻类群落组成更加稳定，种间竞争更小，对环境的利用能力更强。RDA及Pearson分析结果显示，着生藻类优势物种与氨氮、电导率、总碳、溶解性总硅以及硝酸铵盐呈正相关关系，与溶解氧、水温以及溶解性总碳呈现负相关关系。【结论】研究表明：雅砻江中下游水电站的建设对于部分环境因子产生影响，从而使干流不同江段的着生藻类群落特征产生较大的差异。研究成果对雅砻江水生态保护修复具有参考价值。

Abstract

[Objective] To investigate the current status of periphyton communities across the entire mainstream of the Yalong River and the community differences among different river sections. [Methods] Based on a sampling survey of periphyton in 29 cross-sections of the Yalong River mainstream in May 2023, combined with habitat evaluation, the variations in periphyton community structure and the ecological niches of dominant species across different river sections were analyzed. Redundancy analysis(RDA) and Pearson correlation analysis were used to examine the responses of dominant species to environmental factors. [Results] The result showed that a total of 96 species of periphyton were collected, with Bacillariophyta accounting for 89.6%. In the upper reaches, 77 species were identified, with an average cell density of 4 296.3 cells/cm². The dominance of dominant species was relatively balanced, with niche width ranging from 1.35 to 2.05 and niche overlap at 0.628, significantly higher than those in both the better and poorer habitat sections of the middle and lower reaches. This indicated that the upper reaches, unaffected by dam construction, exhibited a more stable composition of periphyton communities, lower interspecies competition, and stronger ability to utilize environmental resources. The RDA and Pearson analysis result showed that the dominant species of periphyton were positively correlated with ammonia nitrogen, conductivity, total carbon, dissolved total silicon, and ammonium nitrate, but negatively correlated with dissolved oxygen, water temperature, and dissolved total carbon. [Conclusion] It has been demonstrated that the construction of hydropower stations in the middle and lower reaches of the Yalong River affects certain environmental factors, leading to significant differences in the characteristics of periphyton communities across different river sections. The findings provide a reference for aquatic ecological conservation and restoration in the Yalong River.

关键词

着生藻类 / 生态位宽度 / 水环境 / 环境因子 / 气候影响 / 影响因素 / 雅砻江

Key words

periphyton / niche width / water environment / environmental factor / climate impact / influence factor / Yalong River

基金资助

国家重点研发计划(2022YFC3202003)

国家重点研发计划(2022YFC3205000)

国家重点研发计划(2021YFC3200202)

国家优秀青年科学基金(52122902)

水生态安全保障人才创新团队项目(WR0145B022021)