Organic sediments are greenhouse gas and nutrient hotspots. They may display lower methane (CH₄) emissions and increase nutrient retention when macrophytes and macrofauna are present, due to oxygen leakage from roots and bioirrigation. We tested this hypothesis via incubations of microcosms reproducing four treatments: bare sediment, sediment with oligochaetes, sediment with macrophytes, and sediment with both organisms. Along a 12-d experiment, CH₄ ebullition in bare sediment (470 ± 13 mmol m⁻²) decreased by 67%, 88%, and 97% in the presence of plants, oligochaetes, and both organisms, respectively. Oligochaetes increased N₂ production by ~ 200 mmol N m⁻² and nitrate consumption by a factor of 4, whereas macrophytes reduced nitrogen losses by ~ 65 mmol N m⁻². All treatments acted as phosphate sink. Results suggest that the maintenance of vegetation and associated macrofauna in organic sediments promotes their combined ecosystem services, resulting in significant reduction of greenhouse gas emission and nutrient release to the water column.

中文翻译：

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蠕虫和沉水植物减少甲烷释放并增加有机沉积物中的养分去除

有机沉积物是温室气体和养分热点。当存在大型植物和大型动物时，由于根部的氧气泄漏和生物灌溉，它们可能会显示出较低的甲烷 (CH ₄ ) 排放量并增加养分保留。我们通过复制四种处理的微观世界的孵化来测试这一假设：裸沉积物、含寡毛纲动物的沉积物、含大型植物的沉积物和含两种生物的沉积物。在为期 12 天的实验中，在植物、寡毛纲动物和这两种生物存在的情况下，裸露沉积物 (470 ± 13 mmol m ^-2 ) 中的CH ₄沸腾分别减少了 67%、88% 和 97%。Oligochaetes 将 N ₂产量增加了约 200 mmol N m ^-2和硝酸盐消耗量增加了 4 倍，而大型植物减少了约 65 mmol N m ^{-2 的}氮损失。所有处理都充当磷酸盐汇。结果表明，有机沉积物中植被和相关大型动物群的维持促进了它们的综合生态系统服务，从而显着减少了温室气体排放和向水体释放的养分。