Mineralization of low molecular weight carbon substrates in soil solution under laboratory and field conditions
Mineralization of low molecular weight carbon substrates in soil solution under laboratory and field conditions
复制标题
DOI：
10.1016/j.soilbio.2012.01.015
复制
发表时间：
2012-05-01
影响因子：
9.7
通讯作者：
Jones, D. L.
中科院分区：
文献类型：
--
作者：
Glanville, H.;Rousk, J.;Jones, D. L.
更详细地了解低分子量（MW）碳（C）基质是如何在根际土壤微生物群落矿化的机制是至关重要的，以准确地模拟陆地碳通量。目前，大多数关于土壤C动态的实验都是在非原位（实验室）进行的，并且可能无法解释原位变化的关键变量（例如温度和土壤含水量）。此外，异地实验往往是高度侵入性的，例如切断根和菌根网络，改变土壤中低分子量分泌物的输入和浓度。本研究的目的是直接比较31种常见的低分子量碳基质在非原位和原位条件下的矿化速率。此外，我们还评估了基质矿化率的年际变化。我们添加微量浓度的31个单独的C-14-标记的常见低分子量C基质到农业草地的表层土壤中，并监测矿化速率通过捕获（CO2）-C-14从土壤中进化超过7 d。我们的研究结果表明，低分子量碳组分对土壤呼吸的贡献是高度重复性的平行研究进行原位或异位之间。我们还发现，个别化合物的矿化差异更多变的年际间在现场比实验室和现场之间。我们的研究结果表明，基于实验室的C矿化数据可以用来可靠地参数化C模型，但多个实验测量应随着时间的推移，以减少模型参数估计的不确定性。(C)2012爱思唯尔有限公司保留所有权利。
A more detailed mechanistic understanding of how low molecular weight (MW) carbon (C) substrates are mineralized within the rhizosphere by soil microbial communities is crucial to accurately model terrestrial C fluxes. Currently, most experiments regarding soil C dynamics are conducted ex-situ (laboratory) and can fail to account for key variables (e.g. temperature and soil water content) which vary in-situ. In addition, ex-situ experiments are often highly invasive, e.g. severing root and mycorrhizal networks, changing the input and concentrations of low MW exudates within soil. The aim of this study was to directly compare the mineralization rates of 31 common low MW C substrates under ex- and in-situ conditions. In addition, we also assessed the inter-annual field variability of substrate mineralization rates. We added trace concentrations of 31 individual C-14-labelled common low MW C substrates into the top soil of an agricultural grassland and monitored the mineralization rates by capturing (CO2)-C-14 evolved from the soil over 7 d. Our results showed that the contribution of low MW C components to soil respiration was highly reproducible between parallel studies performed either in-situ or ex-situ. We also found that differences in the mineralization of individual compounds were more variable inter-annually in the field than between the laboratory and the field. Our results suggest that laboratory-based C mineralization data can be used to reliably parameterize C models but that multiple experimental measurements should be made over time to reduce uncertainty in model parameter estimation. (C) 2012 Elsevier Ltd. All rights reserved.