Methane Emissions from Paludified Boreal Soils in European Russia as Measured and Modelled
Methane Emissions from Paludified Boreal Soils in European Russia as Measured and Modelled
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DOI：
10.1007/s10021-017-0188-y
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发表时间：
2017-09
期刊：
影响因子：
3.7
通讯作者：
J. Schneider;B. Ťupek;M. Lukasheva;Vasiliy Gudyrev;Mikhail Miglovets;H. Jungkunst
中科院分区：
文献类型：
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作者：
J. Schneider;B. Ťupek;M. Lukasheva;Vasiliy Gudyrev;Mikhail Miglovets;H. Jungkunst
空间或时间上的森林-泥炭地过渡带被认为是甲烷(CH4)排放的潜在热点。因此，沼泽化土壤是北方景观生物地球化学的重要组成部分。然而，它们在区域碳循环中的作用仍不清楚。研究了两个森林-泥炭地过渡带、两个湿润林地和两个砍伐地的CH4通量，并与开阔的泥炭地和干燥森林的CH4通量进行了比较。用密闭室技术测得的中位数通量在三个气候不同的年份从−0.04到12.6 mg/m−2 h−1不等。森林泥炭地过渡带的年平均CH4排放量显著低于开阔泥炭地，分别为7.9g/m−2a−1和21.9g/m泥炭地。干燥林地的特征是对甲烷的少量吸收(−为2.3g/m−2a−1)。尽管在过去的20年里，俄罗斯欧洲被砍伐的森林面积急剧增加，但如果这些森林的水位深度保持在1000万厘米以下，它们就不是CH4的来源。过渡带站点的CH4通量对土壤温度的响应大于对地下水位的响应。大气和两个泥炭地之间的CH4通量没有显著差异，尽管可以观察到地下水位的显著差异。受访夏季气象条件由2013年的炎热干燥转为2014年的冷湿；2015年夏季的特点是上半年偏暖偏干，下半年偏冷偏湿。只有在2014年和2013年之间才测量到CH4通量的显著差异。CH4通量和非线性回归的显著差异表明，不同立地类型如旱林、过渡带和开阔的泥炭地的CH4通量需要在景观水平上分别模拟。显然，潜在的过程随着生态系统的不同而不同，在进行大规模建模之前，必须首先了解这些过程(以及区域方面)。
Spatial or temporal forest–peatland transition zones were proposed as potential hot spots of methane (CH4) emissions. Consequently, paludified soils are an important component of boreal landscape biogeochemistry. However, their role in the regional carbon cycle remains unclear. This study presents CH4fluxes from two forest–peatland transition zones, two wet forest sites and two clear-cut sites which were compared to fluxes of open peatlands and dry forest. The median fluxes measured using the closed-chamber technique varied from − 0.04 to 12.6 mg m−2h−1during three climatically different years. The annual mean CH4emissions of the forest–peatland transition zone were significantly lower than the fluxes of the open peatland sites, 7.9 ± 0.5 and 21.9 ± 1.6 g m−2a−1, respectively. The dry forest site was characterized by a small uptake of CH4(− 2.3 ± 0.2 g m−2a−1). Although clear-cut forest area drastically increased in European Russia during the last two decades, if water level depths in these forests remains below 10 cm they do not act as CH4sources. Fluxes of CH4from the transition zone sites showed a higher response to soil temperature than to water table level. Fluxes of CH4between the atmosphere and the two investigated peatlands were not significantly different, although a significant difference in water table level could be observed. The meteorological conditions of the investigated summers changed from being hot and dry in 2013 to cold and wet in 2014; the summer of 2015 was characterized as warmer and drier in the first half and colder and wetter in the second half. Significant differences in CH4fluxes were measured only between 2014 and 2013. Significant differences in CH4fluxes and in nonlinear regressions showed that the CH4fluxes of the different site types such as dry forests, transition zones and open peatlands need to be modelled separately on a landscape level. Obviously, underlying processes vary with the ecosystem and (along with regional aspects) have to be understood first before large-scale modelling is possible.