Decoupled linkage between soil carbon and nitrogen mineralization among soil depths in a subtropical mixed forest
Decoupled linkage between soil carbon and nitrogen mineralization among soil depths in a subtropical mixed forest
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亚热带混交林土壤深度间土壤碳氮矿化之间的解耦联系
DOI：
10.1016/j.soilbio.2017.02.009
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发表时间：
2017-06
影响因子：
9.7
通讯作者：
Feng Liu
中科院分区：
文献类型：
--
作者：
Qiuxiang Tian;Xinggang Wang;Dongya Wang;Min Wang;Chang Liao;Xiaolu Yang;Feng Liu
深层土壤储存了大量的有机碳（C）和氮（N）。然而，鲜为人知的是，在深层土壤中，这复杂的生态系统C和N动态预测土壤C和N矿化之间的相互作用。在20 °C和25 °C条件下进行了为期150 d的室内土壤培养试验，研究了土壤深度和升温对C和N矿化的影响及其关系。从亚热带森林的Hapudalfs剖面中收集土壤，具有三个深度间隔：0-10（表土），10-30（中壤）和30-60 cm（底土）。通过土壤微生物群落水平生理剖面（CLPP）研究了土壤微生物群落在C、N矿化中的作用。结果表明，下层土壤C和N净矿化速率均显著低于表层土壤。与表土相比，下层土壤碳矿化的温度敏感性较低，净氮矿化的温度敏感性较高。表层土壤累积矿化碳与净矿化氮呈显著正相关，20 °C和25 °C时，每矿化碳的矿化氮分别为0.19和0.31。然而，有没有显着的相关性，累积土壤C和净N矿化在底土由于净N矿化量低。活性碳源和可降解有机氮的缺乏限制了土壤氮素的净矿化。表层土壤微生物群落利用较易分解的碳水化合物和羧酸，有利于碳的矿化。相比之下，底土微生物群落对氨基酸（含氮基质）的利用率相对较高，表明存在氮限制。微生物群落对基质的利用模式可以解释不同深度土壤C、N矿化速率的差异，表明微生物群落在土壤C、N矿化过程中起着重要作用。深层土壤C和N矿化之间的解耦关系及其对温度升高的响应差异表明，在生态系统C和N循环中，尤其是在生态系统C动态模型中，深层土壤应与表层土壤分开考虑。
Deep soil stores a large amount of organic carbon (C) and nitrogen (N). However, little is known regarding the interactions between soil C and net N mineralization in deep soil, which complicates the prediction of ecosystem C and N dynamics. In this study, a 150-day laboratory soil incubation experiment was performed under 20 °C and 25 °C to investigate the influence of soil depth and warming on C and net N mineralization and their relationship. Soils were collected from a Hapludalfs profile in a subtropical forest with three depth intervals: 0–10 (topsoil), 10–30 (midsoil), and 30–60 cm (subsoil). Soil microbial community-level physiological profiling (CLPP) was conducted to investigate the role of the microbial community in C and N mineralization. The results demonstrated that both C and net N mineralization rates in subsoil were significantly lower than in topsoil. Compared to topsoil, subsoil had lower temperature sensitivity of C mineralization and relatively higher temperature sensitivity of net N mineralization. Cumulative soil C and net N mineralized were positively correlated in topsoil with the mineralized N per mineralized C showed as 0.19 and 0.31 at 20 °C and 25 °C, respectively. However, there was no significant correlation between cumulative soil C and net N mineralized in subsoil due to the low amount of net N mineralization. The lack of labile C source and degradable organic N were believed to limit the net N mineralization in subsoil. The microbial community in topsoil used relatively more easily decomposable carbohydrates and carboxylic acids, which favored C mineralization. In contrast, the microbial community in subsoil had relatively high utilization of amino acids (N-containing substrates), which indicated there was N limitation. This distinguished substrate utilization patterns of microbial communities could explain the observed C and N mineralization rates among the soil depths, and suggests that the microbial community played an important role in soil C and N mineralization. The decoupled relationships between soil C and net N mineralization in deep soil and their differentiated responses to warmer temperatures among soil depths indicated that deep soil should be considered separately from topsoil for ecosystem C and N cycling, especially for ecosystem C dynamic models.
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DOI：
10.2134/agronmonogr49.c3
发表时间：
2015-10
期刊：
--
影响因子：
--
作者：
D. Olk
通讯作者：
D. Olk
DOI：
10.1073/pnas.1415123112
发表时间：
2015-03-24
影响因子：
11.1
作者：
Koven, Charles D.;Lawrence, David M.;Riley, William J.
通讯作者：
Riley, William J.
影响因子：
8.8
作者：
Bradford, Mark A.;Davies, Christian A.;Wallenstein, Matthew D.
通讯作者：
Wallenstein, Matthew D.
影响因子：
11.6
作者：
J. Rousk;Andrew R. Smith;Davey L. Jones
通讯作者：
J. Rousk;Andrew R. Smith;Davey L. Jones
DOI：
--
发表时间：
1974
期刊：
--
影响因子：
--
作者：
B. W. Avery;C. L. Bascomb
通讯作者：
B. W. Avery;C. L. Bascomb