Greenhouse gases in non-oxygenated and artificially oxygenated eutrophied lakes during winter stratification.
Greenhouse gases in non-oxygenated and artificially oxygenated eutrophied lakes during winter stratification.
复制标题
冬季分层期间非氧化和人工氧化富营养化湖泊中的温室气体。
DOI：
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发表时间：
2001
影响因子：
2.4
通讯作者：
P. Martikainen
中科院分区：
文献类型：
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作者：
J. Huttunen;T. Hammar;J. Alm;J. Silvola;P. Martikainen
溶解的甲烷（CH 4），二氧化碳（CO2），和一氧化二氮（N2 O）的浓度进行了测量，在1997年和1999年冬末在芬兰中北部地区的非充氧和人工充氧，冰覆盖的富营养化湖泊的水柱。在冬季分层，氧气（O2）缺乏季节性冰封，热分层湖泊的关键时期进行采样。氧浓度至少保持在一个中等水平，在整个充氧水柱，而非充氧柱遭受缺氧hypolimnia。超过大气平衡的溶解CH 4的平均浓度在不含氧的水柱中（20.6-154 μ M）大于在含氧的水柱中（0.01-1.41 μ M）。相比之下，平均过量CO2浓度之间的变化较小的非充氧和充氧的网站（0.28-0.47和0.25-0.31毫米，分别）。充氧水柱的N2 O平均过量浓度（0.018-0.032微摩尔）比非充氧水柱（0.005-0.024微摩尔）高。如果假设冬季储存在水柱中的温室气体在春季翻转时释放到大气中，（全球升温潜能值，时间跨度100年），富营养化研究地点的二氧化碳当量（CO2-e）m-2为177至654克，而含氧地点的二氧化碳当量m-2为144至173克。CH 4积累量的增加是非含氧样地GWP较高的主要原因。湖泊生态系统的人为富营养化可以产生增加的CH 4排放量，由于相关的O2消耗的沉积物和水柱。
Concentrations of dissolved methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) were measured in the water columns of non-oxygenated and artificially oxygenated, ice-covered eutrophied lakes in the mid-boreal zone in Finland during late winter 1997 and 1999. Sampling was conducted during winter stratification, the critical period for oxygen (O2) deficiency in seasonally ice-covered, thermally stratified lakes. Oxygen concentrations were maintained at least at a moderate level throughout the oxygenated water columns, whereas the non-oxygenated columns suffered anoxic hypolimnia. The mean concentrations of dissolved CH4 exceeding the atmospheric equilibrium were greater in the non-oxygenated water columns (20.6-154 microM) than in the oxygenated ones (0.01-1.41 microM). In contrast, the mean excess CO2 concentrations varied less between the non-oxygenated and oxygenated sites (0.28-0.47 and 0.25-0.31 mM, respectively). Oxygenated water columns had greater mean excess concentrations of N2O (0.018-0.032 microM) than the non-oxygenated ones (0.005-0.024 microM). If the accumulated greenhouse gas stores in the water columns during winter are assumed to be released to the atmosphere during the spring overturn, the global warming potentials (GWP, time horizon 100 yr) of these potential emissions at the non-oxygenated, eutrophic study sites ranged from 177 to 654 g CO2 equivalent (CO2-e) m-2 compared with 144 to 173 g CO2-e m-2 at the oxygenated sites. The increase in the accumulation of CH4 was the main reason for the higher GWP of the non-oxygenated sites. Anthropogenic eutrophication of lake ecosystems can generate increased CH4 emissions due to associated O2 depletion of their sediment and water column.