The Stable Carbon Isotope Composition of Methane Produced and Emitted from Northern Peatlands

摘要: Stable carbon isotope values, pore water concentration, and flux data for methane (CH 4 ) were compiled 26 peatlands situated in the northern hemisphere to explore relationships between trophic status CH cycling. Methane produced ombrotrophic bogs has δ 13 C values that are significantly more negative than formed fens apparently because of poor dissociation acetic acid or an absence methanogenic archaea capable metabolizing under low pH conditions. The minerotrophic exhibit opposite trend: C(CH become positive with depth rain-fed fens. key zone methanogenesis occurs at shallow depths both types peatland consequently, emitted from (-74.9 ± 9.8‰; n = 42) (-64.8 4.0‰; 38). An abundance graminoids contributes through (1) release root exudates which promotes aceticlastic methanogenesis, (2) rhizosphere oxidization causing localized enrichment , (3) preferential export 12 aerenchyma, also enriches . Emissions blanket raised should be attributed relative isotope-weighted mass balance budgets. Further study is needed have nutrient but a distribution similar