Characterization of soil organic matter in different particle-size fractions in humid subalpine soils by CP/MAS 13C NMR
Characterization of soil organic matter in different particle-size fractions in humid subalpine soils by CP/MAS 13C NMR
复制标题
DOI：
10.1016/s0016-7061(03)00160-5
复制
发表时间：
2003-11-01
期刊：
影响因子：
6.1
通讯作者：
Chiu, CY
中科院分区：
文献类型：
--
作者：
Chen, JS;Chiu, CY
采用固体交叉极化/魔角旋转（CP/MAS）13核磁共振（C-NMR）技术，对亚高山土壤进行粒度分离，研究不同功能土壤有机质（SOM）的碳库。台湾中部海拔2550 ~ 3200 m的铁杉林和沿着坡矮生竹林土壤，降雨量均大于3000 mm。所获得的数据表明，有机质组分不同，根据颗粒大小分布和植被。由于粘粒中脂肪族含量较高，粘粒级与非粘粒级有显著差异。砂粒级一般得到非常相似的结果散装土壤。从粗砂（>250 g）到粘粒（35%），烷基碳（主要是多亚甲基）含量增加。在矮生竹林土壤中，所有颗粒级的O-烷基碳含量都增加，这是由于酚酸与竹凋落物细胞壁多糖的结合。以烷基/O-烷基-C为腐殖化指数，铁杉林和矮竹林土壤各粒级腐殖化程度均为粘粒>细粉粒>粗粉粒>细砂>粗砂。铁杉林土壤的烷基/O-烷基-C比值均高于矮竹草原土壤，表明铁杉林土壤有机质的腐殖化作用高于矮竹草原土壤。13 NMR分析和C/N比值的变化表明，亚高山土壤中细颗粒的柠檬酸类物质的积累有利于烷基碳的积累，而不是芳香碳的积累。土壤中芳香碳含量较低的原因可能与该亚高山地区降水量大有关。(C)2003 Elsevier Science B. V.保留所有权利。
The particle-size separation of subalpine soils was used for delineating the different functional C pools of soil organic matter (SOM) by solid-state cross-polarization/magic-angle-spinning (CP/MAS) C-13 NMR spectroscopy. The soils collected from hemlock forest and dwarfed bamboo grassland along the slope positions at elevations from 2550 to 3200 m in central Taiwan, received high precipitation (>3000 mm). The obtained data show that organic matter fractions differ according to particle-size distribution and vegetations. Being more aliphatic, clay-size fractions were significantly different from bulk soils. Sand-size fractions generally gave very similar results to bulk soils. Alkyl-C (mainly polymethylene) increased from coarse sand (>250 gm) to clay (35%) of O-alkyl-C in all particle-size fractions in dwarfed bamboo grassland soils were attributed to that of the linkage of phenolic acids to cell-wall polysaccharides in bamboo litter. Based on a humification index of alkyl/O-alkyl-C, the humification degrees in particle-size fractions are in the order: clay>fine silt>coarse silt>fine sand>coarse sand in both of hemlock forest and dwarfed bamboo grassland soil., The alkyl/ O-alkyl-C ratios in hemlock forest soil were consistently higher than those in dwarfed bamboo grassland soils, suggesting that humification of SOM is higher in the forest soil than in the dwarfed bamboo grassland soils. The C-13 NMR analysis and the change of C/N ratio of the particle-size fractions indicate that the accumulation of recalcitrant material in fine particle size favors alkyl-C rather than aromatic-C in these subalpine soils. The low content of aromatic-C in soil might be due to the high precipitation in this subalpine area. (C) 2003 Elsevier Science B.V. All rights reserved.