Methane uptake in a temperate forest soil using continuous closed-chamber measurements
Methane uptake in a temperate forest soil using continuous closed-chamber measurements
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DOI：
10.1016/j.agrformet.2015.05.004
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发表时间：
2015-11
影响因子：
6.2
通讯作者：
M. Ueyama;Ryota Takeuchi;Yoshiyuki Takahashi;R. Ide;M. Ataka;Y. Kosugi;Kenshi Takahashi;N. Saigusa
中科院分区：
文献类型：
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作者：
M. Ueyama;Ryota Takeuchi;Yoshiyuki Takahashi;R. Ide;M. Ataka;Y. Kosugi;Kenshi Takahashi;N. Saigusa
利用6个动态密闭腔，利用激光分析仪对温带森林土壤中的甲烷（CH4）通量进行了连续测量。ch4吸收量随着土壤温度的升高和体积含水量的降低而增加，其中使用这两个变量的多元线性回归解释了大约80%的季节变化。根据测量结果，我们的森林作为年度ch4汇，空间变化为25%。增加腔室部署周期，计算出的年ch4汇显著减少：8-13 mg CH4m−2yr−1min−1。不同的初始斜率计算方法对年ch4汇的影响存在显著差异：线性回归法为898±11 mg CH4m−2yr−1，二次回归法为924±8 mg CH4m−2yr−1，指数模型为975±10 mg CH4m−2yr−1。这些结果表明，尽管4-10分钟的部署时间很短，但由于干扰室顶空间和土壤之间的ch4梯度而造成的低估是显著的。微气象双曲松弛涡旋累积法测定的室内ch4通量与冠层尺度ch4通量一致，为731±38 ~ 888±87 mg CH4m−2yr−1。连续动态封闭腔与激光分析仪是一个强大的工具，了解温带森林土壤ch4通量，只要范围的不确定性进行仔细评估。
Methane (CH4) fluxes were continuously measured in a temperate forest soil using six dynamic closed chambers with a laser-based analyzer. CH4uptake increased with an increase in soil temperature and a decrease in volumetric water content, where multiple linear regressions using the two variables explained approximately 80% of the seasonal variations. Based on the measurements, our forest acted as an annual CH4sink with a spatial variation of 25%. The calculated annual CH4sink significantly decreased by increasing the chamber deployment period: 8–13 mg CH4m−2yr−1min−1. The annual CH4sink was significantly different using different calculation methods for the initial slope: 898 ± 11 mg CH4m−2yr−1using a linear regression, 924 ± 8 mg CH4m−2yr−1using a quadratic regression, and 975 ± 10 mg CH4m−2yr−1using an exponential model. These results indicate that underestimations due to disturbing the CH4gradient between chamber headspaces and soils were significant despite of the short deployment periods of 4–10 min. Chamber-based fluxes were consistent with canopy-scale CH4fluxes by the micrometeorological hyperbolic relaxed eddy accumulation method: sink of 731 ± 38 to 888 ± 87 mg CH4m−2yr−1. Continuous dynamic closed chambers with laser-based analyzers are a powerful tool to understand CH4fluxes in temperate forest soils, as long as a range of uncertainties are carefully evaluated.