Abstract Excess reactive nitrogen (N) flows from agricultural, suburban, and urban systems to coasts, where it causes eutrophication. Coastal wetlands take up some of this N, thereby ameliorating the impacts on nearshore waters. Although the consequences of N on coastal wetlands have been extensively studied, the effect of the specific form of N is not often considered. Both oxidized N forms (nitrate, NO3−) and reduced forms (ammonium, NH4+) can relieve nutrient limitation and increase primary production. However, unlike NH4+, NO3− can also be used as an electron acceptor for microbial respiration. We present results demonstrating that, in salt marshes, microbes use NO3− to support organic matter decomposition and primary production is less stimulated than when enriched with reduced N. Understanding how different forms of N mediate the balance between primary production and decomposition is essential for managing coastal wetlands as N enrichment and sea level rise continue to assail our coasts.

中文翻译：

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并非所有的氮都是平等的：沿海湿地中硝酸盐和铵富集的不同影响

摘要 过量的活性氮 (N) 从农业、郊区和城市系统流向海岸，导致富营养化。沿海湿地吸收了其中的一部分氮，从而减轻了对近岸水域的影响。尽管 N 对沿海湿地的影响已得到广泛研究，但通常不考虑 N 特定形式的影响。氧化氮形式（硝酸盐，NO3-）和还原形式（铵，NH4+）都可以缓解养分限制并增加初级产量。然而，与 NH4+ 不同，NO3- 也可以用作微生物呼吸的电子受体。我们展示的结果表明，在盐沼中，微生物使用 NO3− 来支持有机物分解，与富含还原 N 时相比，初级生产受到的刺激较小。