Peatlands have acted as C-sinks for millennia, storing large amounts of carbon, of which a significant amount is yearly released as methane (CH₄). Sphagnum mosses are a key genus in many peat ecosystems and these mosses live in close association with methane-oxidizing and nitrogen-fixing microorganisms. To disentangle mechanisms which may control Sphagnum-associated methane-oxidation and nitrogen-fixation, we applied four treatments to Sphagnum mosses from a pristine peatland in Finland: nitrogen fertilization, phosphorus fertilization, CH₄ addition and light. N and P fertilization resulted in nutrient accumulation in the moss tissue, but did not increase Sphagnum growth. While net CO₂ fixation rates remained unaffected in the N and P treatment, net CH₄ emissions decreased because of enhanced CH₄ oxidation. CH₄ addition did not affect Sphagnum performance in the present set-up. Light, however, clearly stimulated the activity of associated nitrogen-fixing and methane-oxidizing microorganisms, increasing N₂ fixation rates threefold and CH₄ oxidation rates fivefold. This underlines the strong connection between Sphagnum and associated N₂ fixation and CH₄ oxidation. It furthermore indicates that phototrophy is a strong control of microbial activity, which can be directly or indirectly.

几千年来，泥炭地一直充当碳汇，储存了大量的碳，其中每年有大量碳以甲烷 (CH ₄ ) 的形式释放。泥炭藓是许多泥炭生态系统中的一个关键属，这些苔藓与甲烷氧化和固氮微生物密切相关。为了阐明可能控制与泥炭藓相关的甲烷氧化和固氮的机制，我们对芬兰原始泥炭地的泥炭藓进行了四种处理：施氮肥、施磷肥、添加 CH ₄和光照。氮肥和磷肥导致苔藓组织中养分积累，但没有增加泥炭藓的生长。虽然在 N 和 P 处理中 CO ₂净固定率未受影响，但由于 CH 4 氧化增强，CH 4 净排放量_有所下降。CH ₄添加不会影响当前设置中的泥炭藓性能。然而，光明显刺激了相关固氮和甲烷氧化微生物的活性，使 N ₂固定率增加三倍，CH ₄氧化率增加五倍。这强调了泥炭藓与相关的 N ₂固定和 CH ₄氧化之间的密切联系。它还表明光养是对微生物活动的强有力的控制，这可以是直接或间接的。