14 C mean residence time and its relationship with thermal stability and molecular composition of soil organic matter: A case study of deciduous and coniferous forest types
14 C mean residence time and its relationship with thermal stability and molecular composition of soil organic matter: A case study of deciduous and coniferous forest types
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14℃平均停留时间及其与热稳定性和土壤有机质分子组成的关系：以落叶林和针叶林类型为例
DOI：
10.1016/j.geoderma.2017.08.023
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发表时间：
2017
期刊：
影响因子：
6.1
通讯作者：
Parr, Thomas B.
中科院分区：
文献类型：
--
作者：
Ohno, Tsutomu;Heckman, Katherine A.;Plante, Alain F.;Fernandez, Ivan J.;Parr, Thomas B.
土壤有机质(SOM)在全球陆地碳循环中起着至关重要的作用，更好地了解土壤有机质稳定性所涉及的土壤过程对于确定气候驱动的土壤过程变化将如何影响碳动态是至关重要的。用~(14)C谱、分析热分析和超高分辨质谱仪研究了落叶和针叶林植被类型和土壤深度对土壤C稳定性的影响。沉积B层土壤的~(14)C平均停留时间(MRT)落叶土平均为1350年，针叶土为795年。不同森林类型矿物土壤的MRT差异可能是由于针叶土壤中的SOM饱和了可提取的Fe和Al矿物结合部位，使得现代SOM从O层向土壤剖面的运移比落叶土壤剖面中的非饱和矿物更大。在B层土壤下部，落叶水提芳香SOM组分的分子质量分布比上部向低质量范围移动，表明高质量芳香族组分优先被吸附。针叶土中芳香族组分质量分布的变化比落叶土小得多，支持可提取金属矿物已达到饱和的观点。我们的结论是，现代O层SOM向针叶土壤剖面中较低的矿物B层的较大运移导致了其放射性碳的富集度和估算的MRT缩短。我们的发现强调了森林植被类型、土壤深度和运输机制对土壤有机质稳定性的重要性，并对陆地C循环中森林组成的变化提出了重要的生态学意义。
Soil organic matter (SOM) plays a critical role in the global terrestrial carbon cycle, and a better understanding of soil processes involved in SOM stability is essential to determine how projected climate-driven changes in soil processes will influence carbon dynamics. We used14C signature, analytical thermal analysis, and ultrahigh resolution mass spectrometry to determine the influence of deciduous and coniferous forest vegetation type and soil depth on the stability of soil C. The14C mean residence time (MRT) of the illuvial B horizon soils averaged 1350 years for the deciduous soils and 795 years for the coniferous soils. The difference of MRT between mineral soils by forest type may be due to the saturation of extractable Fe and Al minerals binding sites by SOM in the coniferous soils, allowing greater transport of modern SOM from the O horizon down the soil profile, as compared with the non-saturated minerals in the deciduous soil profile. The molecular mass distribution of the deciduous water-extractable aromatic SOM fraction was shifted to a lower mass range in the lower portion of B horizon soil compared with the upper portion, indicating preferential sorption of the higher mass aromatic fraction. The shift in the mass distribution of the aromatic fraction in the coniferous soil was much less than in the deciduous soil, which supports the view that the extractable metal minerals had reached saturation. We conclude that greater transport of modern O horizon SOM to the lower mineral B horizons in the coniferous soil profile resulted in its radiocarbon enrichment and shorter estimated MRT. Our findings highlight the importance of forest vegetation type, soil depth and transport mechanisms on SOM stability, and suggest important ecological implications for changes in forest composition on the terrestrial C cycle.
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影响因子：
2.2
作者：
S. S. Iyengar-S.;L. Zelazny;D. C. Martens
通讯作者：
S. S. Iyengar-S.;L. Zelazny;D. C. Martens
影响因子：
8.3
作者：
STUIVER, M;POLACH, HA
通讯作者：
POLACH, HA
影响因子：
5.5
作者：
MINDERMA.G
通讯作者：
MINDERMA.G
影响因子：
5
作者：
Seidel M;Beck M;Riedel T;Waska H;Suryaputra IGNA;Schnetger B;Niggemann J;Simon M;Dittmar T
通讯作者：
Dittmar T
缅因州的熊溪流域：配对流域实验
DOI：
--
发表时间：
1999
期刊：
影响因子：
--
作者：
S. Norton;I. Fernandez
通讯作者：
I. Fernandez