Nitrogen removal is essential for restoring eutrophic lakes. Microorganisms and aquatic plants in lakes are both crucial for removing excess nitrogen. However, microplastic (MP) pollution and the invasion of exotic aquatic plants have become increasingly serious in lake ecosystems due to human activity and plant-dominant traits. This field mesocosm study explored how the diversity of invasive submerged macrophytes affects denitrification (DNF), anammox (ANA), and dissimilatory nitrate reduction to ammonium (DNRA) in lake sediments with varying MPs. Results showed that invasive macrophytes suppressed DNF rates, but DNRA and ANA were less sensitive than DNF to the diversity of invasive species. Sediment MPs increased the biomass of invasive species more than native species, but did not affect microbial processes. The effects of MPs on nitrate dissimilatory reduction were process-specific. MPs increased DNF rates and the competitive advantage of DNF over DNRA by changing the sediment environment. The decoupling of DNF and ANA was also observed, with increased DNF rates and decreased ANA rates. The study findings suggested new insights into how the invasion of exotic submerged macrophytes affects the sediment nitrogen cycle complex environments.

中文翻译：

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入侵性沉水植物多样性是否会影响具有不同微塑料的沉积物中的异化硝酸盐还原过程？


除氮对于恢复富营养化湖泊至关重要。湖泊中的微生物和水生植物对于去除多余的氮至关重要。然而，由于人类活动和植物主导性状，湖泊生态系统中的微塑料（MP）污染和外来水生植物的入侵日益严重。这项野外中生态系统研究探讨了入侵性沉水植物的多样性如何影响具有不同 MP 的湖泊沉积物中的反硝化 (DNF)、厌氧氨氧化 (ANA) 和异化硝酸盐还原成铵 (DNRA)。结果表明，入侵大型植物抑制了 DNF 率，但 DNRA 和 ANA 对入侵物种多样性的敏感度低于 DNF。沉积物 MP 增加了入侵物种的生物量，但不影响微生物过程。 MP 对硝酸盐异化还原的影响是特定于过程的。 MP 通过改变沉积物环境提高了 DNF 率以及 DNF 相对于 DNRA 的竞争优势。还观察到 DNF 和 ANA 的解耦，DNF 率增加，ANA 率下降。研究结果对外来沉水植物的入侵如何影响沉积物氮循环复杂环境提出了新的见解。