Here we use a top-down and bottom-up approach in landscape ecology to analyze the active microbes processing methane fluxes (FCH₄) in seasonally flooded-forest (FOR) and -traditional farming systems (TFS) in Amazonian floodplains flooded with black, white, and clear water. Our results revealed higher CH₄ emissions from water-atmosphere interface in clear water floodplain, followed by black and white water floodplain, respectively. Active methanogenic and methanotrophic taxa were ubiquitous at 0–15 and 15–30 cm soil layer in FOR and TFS, with differences among the water types with respect to the richness, evenness and diversity of the methanogenic communities. These ecological results were not generalizable regarding to FOR and TFS sites, soil layers, and non-flooded and flooded periods. Despite the predominant oxidation of CH₄ in the non-flooded period, higher richness and diversity of methanotrophs were revealed for FOR and TFS in the flooded period. In turn, the structure of the methanogenic and methanotrophic communities and their variation were influenced mainly by soil physicochemical factors, water type, soil depth and the presence of nitrifiers, as Nitrososphaera and Nitrospira. Our study reveals a signature across methanotrophic communities in soils from Amazon floodplain with different water types, with a putative disproportionate role of NC10 phylum in CH₄ mitigation in natural and agricultural Amazonian floodplains. These findings open the possibilities to explore the role of NC10 phylum in the carbon cycling in Amazon.

在这里，我们在景观生态学中使用自上而下和自下而上的方法来分析亚马逊河泛滥平原季节性洪水森林 (FOR) 和传统农业系统 (TFS) 中处理甲烷通量 ( F CH ₄ )的活性微生物，白色，清澈的水。我们的结果显示更高的 CH ₄清水泛滥平原的水-大气界面排放，其次是黑水泛滥平原和白水泛滥平原。活跃的产甲烷和甲烷营养类群在 FOR 和 TFS 的 0-15 和 15-30 cm 土层普遍存在，不同水类型在产甲烷群落的丰富度、均匀度和多样性方面存在差异。这些生态结果对于 FOR 和 TFS 站点、土壤层以及非洪水和洪水时期是不可推广的。尽管 CH ₄主要氧化在非淹水期，淹水期的FOR和TFS显示出较高的甲烷氧化菌丰富度和多样性。反过来，产甲烷菌和甲烷氧化菌群落的结构及其变化主要受土壤理化因素、水类型、土壤深度和硝化菌存在的影响，如Nitrososphaera和Nitrospira。我们的研究揭示了具有不同水类型的亚马逊洪泛区土壤中甲烷营养群落的特征，其中 NC10 门在自然和农业亚马逊洪泛区的CH ₄减缓中发挥了不成比例的作用。这些发现为探索 NC10 门在亚马逊碳循环中的作用开辟了可能性。