Non-flooded riparian Amazon trees are a regionally significant methane source.
Non-flooded riparian Amazon trees are a regionally significant methane source.
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DOI：
10.1098/rsta.2020.0446
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发表时间：
2022-01-24
期刊：
影响因子：
--
通讯作者：
Enrich-Prast A
中科院分区：
文献类型：
--
作者：
Gauci V;Figueiredo V;Gedney N;Pangala SR;Stauffer T;Weedon GP;Enrich-Prast A
洪水适应的树木最近被确定为主要的出口途径土壤产生的甲烷（CH 4）在森林湿地。这增加了土壤柱深处产生的CH 4可以通过树根排放到大气中的可能性，即使地下水位（WT）低于地表。如果正确的话，这将对模拟工作提出挑战，因为洪水往往决定了生态系统CH 4产生和排放的空间范围。在这里，我们研究了CH 4交换的树木，土壤和水生表面在森林中经历了一个动态的WT在三个洪泛区的位置跨越亚马逊流域在四个水文不同的时间从2017年4月至2018年1月。树干排放量的数量级大于土壤或水生表面排放量，并表现出强烈的关系WT深度低于表面（小于0）。我们估计，亚马逊河岸洪泛区边缘与WT < 0贡献2.2-3.6 Tg CH 4 yr-1的大气中除了淹没树木排放约12.7-21.1 Tg CH 4 yr-1。将我们的方法应用于所有热带湿地阔叶树，估计非洪泛平原树木通量为6.4 Tg CH 4 yr−1，占洪泛热带树木通量约37.1 Tg CH 4 yr−1的17%，表明这些生态系统在扩大洪泛土地以外的有效CH 4排放面积方面的重要性。这篇文章是讨论会议议题“甲烷上升：变暖是变暖的饲料吗？”(part两分钟。
Inundation-adapted trees were recently established as the dominant egress pathway for soil-produced methane (CH4) in forested wetlands. This raises the possibility that CH4 produced deep within the soil column can vent to the atmosphere via tree roots even when the water table (WT) is below the surface. If correct, this would challenge modelling efforts where inundation often defines the spatial extent of ecosystem CH4 production and emission. Here, we examine CH4 exchange on tree, soil and aquatic surfaces in forest experiencing a dynamic WT at three floodplain locations spanning the Amazon basin at four hydrologically distinct times from April 2017 to January 2018. Tree stem emissions were orders of magnitude larger than from soil or aquatic surface emissions and exhibited a strong relationship to WT depth below the surface (less than 0). We estimate that Amazon riparian floodplain margins with a WT < 0 contribute 2.2–3.6 Tg CH4 yr−1 to the atmosphere in addition to inundated tree emissions of approximately 12.7–21.1 Tg CH4 yr−1. Applying our approach to all tropical wetland broad-leaf trees yields an estimated non-flooded floodplain tree flux of 6.4 Tg CH4 yr−1 which, at 17% of the flooded tropical tree flux of approximately 37.1 Tg CH4 yr−1, demonstrates the importance of these ecosystems in extending the effective CH4 emitting area beyond flooded lands. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 2)'.
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影响因子：
9.4
作者：
Pitz, Scott;Megonigal, J. Patrick
通讯作者：
Megonigal, J. Patrick
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Hess, Laura L.;Melack, John M.;Novo, Evlyn M. L. M.
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影响因子：
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通讯作者：
Van de Bogert, Matthew C.
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作者：
Melack, JM;Hess, LL;Novo, EMLM
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