Mangroves forests may be important sinks of carbon in coastal areas but upon their death, these forests may become net sources of carbon dioxide (CO) and methane (CH) to the atmosphere. Here we assessed the spatial and temporal variability in soil CO and CH fluxes from dead mangrove forests and paired intact sites in SE-Brazil. Our findings demonstrated that during warmer and drier conditions, CO soil flux was 183 % higher in live mangrove forests when compared to the dead mangrove forests. Soil CH emissions in live forests were > 1.4-fold higher than the global mangrove average. During the wet season, soil GHG emissions dropped significantly at all sites. During warmer conditions, mangroves were net sources of GHG, with a potential warming effect (GWP100) of 32.9 ± 10.2 (±SE) Mg COe ha y. Overall, we found that dead mangroves did not release great amounts of GHG after three years of forest loss.

中文翻译：

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巴西东南部死亡红树林和天然红树林的土壤温室气体排放

红树林可能是沿海地区重要的碳汇，但在它们死亡后，这些森林可能成为大气中二氧化碳 (CO) 和甲烷 (CH) 的净来源。在这里，我们评估了巴西东南部死去的红树林和配对的完整地点土壤二氧化碳和甲烷通量的时空变化。我们的研究结果表明，在温暖和干燥的条件下，与死红树林相比，活红树林中的二氧化碳土壤通量高出 183%。活林土壤 CH 排放量比全球红树林平均排放量高 1.4 倍以上。雨季期间，所有地点的土壤温室气体排放量均大幅下降。在温暖的条件下，红树林是温室气体的净来源，潜在的变暖效应（GWP100）为 32.9 ± 10.2 (±SE) Mg COe ha y。总体而言，我们发现在森林消失三年后，死亡的红树林并没有释放大量温室气体。