METHANE FLUX FROM THE CENTRAL AMAZONIAN FLOODPLAIN
METHANE FLUX FROM THE CENTRAL AMAZONIAN FLOODPLAIN
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DOI：
10.1029/jd093id02p01571
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发表时间：
1988-02-20
影响因子：
4.4
通讯作者：
MELACK, JM
中科院分区：
文献类型：
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作者：
BARTLETT, KB;CRILL, PM;MELACK, JM
从1985年7月18日至9月2日期间，共有186个甲烷测量，从三个主要的亚马逊河漫滩环境的开放水域湖泊，淹没的森林，和浮动草席。这些数据表明，排放量在开放水域湖泊上最低，通量平均为27 ± 4.7 mg CH4m−2d−1（n= 41）。来自被洪水淹没的森林和草垫的通量明显更高。淹没森林的排放量平均为192±26.8 mg CH4m−2d−1（n= 90），而漂浮草垫的排放量平均为230±72.2 mg CH4m−2d−1（n= 55）。至少有三种传输过程对对流层排放有贡献：沉积物的沸腾、沿着浓度梯度从沉积物到上覆水再到空气的扩散以及通过水生植物的根和茎的传输。测量表明，这些过程中的前两个是最重要的。淹没森林的扩散通量平均为50.5±11.0 mg CH4m−2d−1，而漂浮垫的平均值为43.7±11.8 mg CH4m−2d−1。开放沃茨的扩散通量平均为8.3±1.9 mg CH4m−2d−1。通过气泡排放的甲烷为168±32.2（淹没森林），346±128 mg CH4m−2d−1（漂浮草）和17.3±5.2（开放水域）。我们估计，平均而言，气泡占开放水域流量的49%，占淹没森林流量的54%，占浮垫流量的64%。如果我们将我们的测量应用于整个亚马逊河漫滩，我们计算出该地区可以提供高达12%的估计全球甲烷天然来源。
A total of 186 methane measurements from the three primary Amazon floodplain environments of open water lakes, flooded forests, and floating grass mats were made over the period from July 18 through September 2, 1985. These data indicate that emissions were lowest over open water lakes, where flux averaged 27 plus or minus a standard error of 4.7 mg CH4m−2d−1(n= 41). Flux from flooded forests and grass mats was significantly higher. Emissions from flooded forests averaged 192±26.8 mg CH4m−2d−1(n= 90), while those from floating grass mats averaged 230±72.2 mg CH4m−2d−1(n= 55). At least three transport processes contribute to tropospheric emissions: ebullition from sediments, diffusion along the concentration gradient from sediment to overlying water to air, and transport through the roots and stems of aquatic plants. Measurements indicate that the first two of these processes are most significant. Diffusive flux from flooded forests averaged 50.5±11.0 mg CH4m−2d−1, while that from floating mats averaged 43.7±11.8 mg CH4m−2d−1. Diffusive flux from open waters averaged 8.3±1.9 mg CH4m−2d−1. Emissions through bubbling were 168±32.2 (flooded forest), 346±128 mg CH4m−2d−1(floating grasses), and 17.3±5.2 (open water). We estimate that on the average, bubbling makes up 49% of the flux from open water, 54% of that from flooded forests, and 64% of that from floating mats. If we apply our measurements to the entire Amazonian floodplain, we calculate that the region could supply up to 12% of the estimated global natural sources of methane.