【摘要】 探究不同覆盖密度的水生植物（水葫芦、水浮萍、水花生）在其生长盛期及人工打捞后对河道关键水质参数的差异化影响，旨在为河湖水生态管理中的科学打捞决策提供定量依据。在江苏省东台市典型河道布设监测断面，按水草种类与覆盖密度（零星、1/3、满河）分组，于生长旺季（7—9月）及打捞后（10月）系统监测水体溶解氧（DO）、氨氮（NH₃-N）和总磷（TP）质量浓度变化，并结合单因素方差分析进行统计检验。结果表明，生长盛期，水草覆盖密度与DO呈极显著负相关（P<0.01），与NH₃-N、TP呈极显著正相关（P<0.01）；满河覆盖断面DO平均质量浓度较零星断面低4.2～5.8 mg/L，而NH₃-N与TP平均质量浓度则分别为零星断面的2.5～3.8倍和2.1～3.2倍；打捞作业后，所有断面水质均显著改善，DO平均回升32.7%～68.4%,NH₃-N和TP平均降幅分别为41.5%～59.2%和36.8%～54.1%。3种水生植物中，水葫芦对DO的抑制效应及对营养盐的富集效应最为显著。高密度水生植物是导致水体缺氧与内源营养盐负荷升高的关键风险因子；适时打捞是快速移除内源污染、逆转水质恶化趋势的有效措施。建议将水草覆盖度控制在30%以下，并于生长末期（秋季衰亡前）实施打捞，以兼顾生态效益与水质安全。更多还原

【Abstract】 Exploring the differential effects of aquatic plants（water hyacinth, water duckweed, water peanut）with different coverage densities on key water quality parameters of rivers during their peak growth period and after artificial salvage, aiming to provide quantitative basis for scientific salvage decisions in river and lake ecological management. Monitoring sections were set up in typical river channels in Dongtai City, Jiangsu Province, and grouped according to water grass species and coverage density（sporadic, 1/3, full river）. During the peak growth season（from July to September）and after salvage（October）, the concentration changes of dissolved oxygen（DO）,ammonia nitrogen（NH₃-N）, and total phosphorus（TP）in the water were systematically monitored, and statistical tests were conducted using one-way ANOVA. During the peak growth period, the coverage density of aquatic plants showed a highly significant negative correlation with dissolved oxygen（DO）（P<0.01）, and a highly significant positive correlation with NH₃-N and TP（P<0.01）. The average dissolved oxygen（DO）concentration in the river sections fully covered with aquatic plants was 4.2-5.8 mg/L lower than that in the sporadic coverage sections, while the average concentrations of ammonia nitrogen（NH₃-N）and total phosphorus（TP）were 2.5-3.8 times and 2.1-3.2 times those in the sporadic covered sections, respectively. After the salvage operation, the water quality of all sections significantly improved, with an average increase of 32.7%～68.4% in dissolved oxygen（DO）, an average decrease of 41.5%～59.2% in NH₃-N, and 36.8%～54.1% in TP. Among the three aquatic plants, water hyacinth has the most significant inhibitory effect on dissolved oxygen（DO）and nutrient enrichment effect. High density aquatic plants are key risk factors leading to water hypoxia and increased endogenous nutrient load; Timely salvage is an effective measure to quickly remove internal pollution and reverse the trend of water quality deterioration. It is recommended to control the coverage of aquatic plants below 30% and carry out salvage during the late growth stage（before autumn decline）to balance ecological benefits and water quality safety.更多还原