| Autor: |
Li, Xiaxia1,2,3 (AUTHOR), Chen, Kai4 (AUTHOR), Wang, Chao1,5 (AUTHOR) wangchao@iwhr.com, Zhuo, Tianyu6 (AUTHOR), Li, Hongtao7 (AUTHOR), Wu, Yong7 (AUTHOR), Lei, Xiaohui5 (AUTHOR), Li, Ming8 (AUTHOR), Chen, Bin9 (AUTHOR), Chai, Beibei1,2,3 (AUTHOR) cbb21@163.com |
| Předmět: |
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| Zdroj: |
Journal of Environmental Sciences (Elsevier). Feb2025, Vol. 148, p375-386. 12p. |
| Abstrakt: |
• The accuracy of the eDNA method of planktic algae in the Tuojiang River Basin was higher than that of conventional survey methods. • SEM analysis showed algae growth was significantly affected by N/P ratio, and was mainly limited by phosphorus. At the same time, SEM also obtained the causal relationship of each water environment and water quality parameters. • Mantel analysis showed the phytoplankton in TRB water exhibits strong correlations with NH 3 -N, COD, TDS, TN, and TP and all of which were statistically significant relationships. • The factors influencing phytoplankton growth in the TRB were consistent with the observed and monitored data. Tuojiang River Basin is a first-class tributary of the upper reaches of the Yangtze River—which is the longest river in China. As phytoplankton are sensitive indicators of trophic changes in water bodies, characterizing phytoplankton communities and their growth influencing factors in polluted urban rivers can provide new ideas for pollution control. Here, we used direct microscopic count and environmental DNA (eDNA) metabarcoding methods to investigate phytoplankton community structure in Tuojiang River Basin (Chengdu, Sichuan Province, China). The association between phytoplankton community structure and water environmental factors was evaluated by Mantel analysis. Additional environmental monitoring data were used to pinpoint major factors that influenced phytoplankton growth based on structural equation modeling. At the phylum level, the dominant phytoplankton taxa identified by the conventional microscopic method mainly belonged to Bacillariophyta, Chlorophyta , and Cyanophyta , in contrast with Chlorophyta, Dinophyceae , and Bacillariophyta identified by eDNA metabarcoding. In α-diversity analysis, eDNA metabarcoding detected greater species diversity and achieved higher precision than the microscopic method. Phytoplankton growth was largely limited by phosphorus based on the nitrogen-to-phosphorus ratios > 16:1 in all water samples. Redundancy analysis and structural equation modeling also confirmed that the nitrogen-to-phosphorus ratio was the principal factor influencing phytoplankton growth. The results could be useful for implementing comprehensive management of the river basin environment. It is recommended to control the discharge of point- and surface-source pollutants and the concentration of dissolved oxygen in areas with excessive nutrients (e.g., Jianyang–Ziyang). Algae monitoring techniques and removal strategies should be improved in 201 Hospital, Hongrihe Bridge and Colmar Town areas. [Display omitted] [ABSTRACT FROM AUTHOR] |
| Databáze: |
GreenFILE |
| Externí odkaz: |
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Full Text from ScienceDirect