When the Source of Flooding Matters: Divergent Responses in Carbon Fluxes in an Alaskan Rich Fen to Two Types of Inundation
When the Source of Flooding Matters: Divergent Responses in Carbon Fluxes in an Alaskan Rich Fen to Two Types of Inundation
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DOI：
10.1007/s10021-019-00460-z
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发表时间：
2020-09-01
期刊：
影响因子：
3.7
通讯作者：
Turetsky, M. R.
中科院分区：
文献类型：
--
作者：
Euskirchen, E. S.;Kane, E. S.;Turetsky, M. R.
随着永久冻土的融化，受地下水影响的富沼泽的范围在北方地区不断扩大。这些沼泽在深层有机沉积物中储存了大量的碳，其范围的增加与降雨和径流的增加相结合。我们研究的碳和水通量的年际变化，在阿拉斯加内陆，包括早期（5月至6月）和中后期（7月至9月）干燥和潮湿的时期，与早期的季节湿润期相一致的融雪径流和后期的季节湿润期相一致的洪水从降雨。从2011年5月到2018年12月，该沼泽估计为170 +/- 64 g C m（-2）的CO2来源。当控制土壤温度，净CO（2）吸收是最大的在早期的季节在干燥条件下，地下水位的位置低于表面，和最少的在中后期的季节时，地下水位的位置高于表面。甲烷排放量最低，在雨季早期和最大的雨季后期。我们的研究结果表明，重要的是要考虑的季节性的潮湿和干燥的时期，以及如何这些可能与径流从融雪与降雨在北方丰富的沼泽，当考虑到每年的净碳平衡，并作出准确的预测，碳平衡在北方湿地。
The extent of groundwater-influenced rich fens is increasing across northern regions as permafrost thaws. The increase in the extent of these fens, which store large amounts of carbon in deep organic deposits, is coupled to increases in rainfall and runoff. We examine interannual variations in carbon and water fluxes at a rich fen in interior Alaska that included early (May-June) and mid-late (July-September) dry and wet periods, with early season wet periods coincident with runoff from snowmelt and later season wet periods coincident with inundation from rainfall. From May 2011 to December 2018, the fen was estimated as a 170 +/- 64 g C m(-2)source of CO2. When controlling for soil temperature, net CO(2)uptake was greatest during the early season under dry conditions, with the water table position below the surface, and least during the mid-late season when the water table position was above the surface. Methane emissions were lowest during early season wet periods and greatest during late season wet periods. Our results suggest that it is important to consider the seasonality of wet and dry periods, and how these may potentially be related to runoff from snowmelt versus rainfall in boreal rich fens, when considering the annual net C balance and making accurate projections of carbon balance in northern wetlands.