Assessment of the soil CO2 gradient method for soil CO2 efflux measurements: comparison of six models in the calculation of the relative gas diffusion coefficient
Assessment of the soil CO2 gradient method for soil CO2 efflux measurements: comparison of six models in the calculation of the relative gas diffusion coefficient
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DOI：
10.1111/j.1600-0889.2009.00445.x
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发表时间：
2010-01
期刊：
影响因子：
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通讯作者：
Natchaya Pingintha;M. Leclerc;J. Beasley;Gengsheng Zhang;C. Senthong
中科院分区：
文献类型：
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作者：
Natchaya Pingintha;M. Leclerc;J. Beasley;Gengsheng Zhang;C. Senthong
本文采用改进的土壤梯度法估算土壤CO2通量。使用六种不同的模型来确定相对气体扩散系数（ε）。一个加权谐波平均是用来估计土壤CO2扩散系数，产生一个更好的估计土壤CO2排放。然后将所得的土壤CO2流出结果与用土壤室测量的土壤CO2流出进行比较。根据所使用的CO2排放模型的选择，使用梯度法估算的土壤CO2排放量合理地近似于使用土壤室法获得的排放量。此外，通过这种改进的方法得到的估计土壤CO2通量是很好地描述了土壤温度的指数函数在0.05米的深度与温度敏感性（Q10）为1.81和土壤水分的线性函数在0.12米的深度，在一般协议与以前的研究结果。这些结果表明，梯度法是一个实用的成本效益的手段来衡量土壤CO2排放量。从本研究的结果表明，梯度法可以成功地用于测量土壤CO2的排放量，提供适当的注意是明智地使用适当的扩散系数。
This paper uses a refined soil gradient method to estimate soil CO2 efflux. Six different models are used to determine the relative gas diffusion coefficient (ξ ). A weighted harmonic averaging is used to estimate the soil CO2 diffusion coefficient, yielding a better estimate of soil CO2 efflux. The resulting soil CO2 efflux results are then compared to the soil CO2 efflux measured with a soil chamber. Depending on the choice of ξ model used, the estimated soil CO2 efflux using the gradient method reasonably approximates the efflux obtained using the soil chamber method. In addition, the estimated soil CO2 efflux obtained by this improved method is well described by an exponential function of soil temperature at a depth of 0.05 m with the temperature sensitivity (Q10) of 1.81 and a linear function of soil moisture at a depth of 0.12 m, in general agreement with previous findings. These results suggest that the gradient method is a practical cost-effective means to measure soil CO2 emissions. Results from the present study suggest that the gradient method can be used successfully to measure soil CO2 efflux provided that proper attention is paid to the judicious use of the proper diffusion coefficient.