文献类型：期刊文献

英文题名：Afforestation Alters the Molecular Composition of Soil Organic Matter in the Central Loess Plateau of China

作者：Song, Xueshu[1,2] Guo, Jingwen[1,2] Wang, Xiao[3] Du, Zhangliu[3] Ren, Rongxiu[1] Lu, Sen[1,2] He, Chunxia[1]

第一作者：Song, Xueshu

通信作者：Lu, S[1];Lu, S[2]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, Key Lab Tree Breeding & Cultivat State Forestry &, Beijing 100091, Peoples R China;[2]Nanjing Forestry Univ, Coinnovat Ctr Sustaintable Forestry Southern China, Nanjing 210037, Peoples R China;[3]China Agr Univ, Coll Resources & Environm Sci, Beijing 100193, Peoples R China

年份：2023

卷号：14

期号：7

外文期刊名：FORESTS

收录：;EI(收录号：20233114473772);Scopus(收录号：2-s2.0-85166207047);WOS:【SCI-EXPANDED(收录号:WOS:001036058300001)】；

基金：This research was supported by the Fundamental Research Funds of CAF (CAFYBB2020QD002-2).

语种：英文

外文关键词：soil organic matter; biomarker; nuclear magnetic resonance (NMR); lipid; solvent extract; lignin-derived phenol

摘要：Many studies have been conducted on organic carbon changes under different land use patterns, but studies and data concerning changes in the molecular composition of soil organic matter (SOM) during land use conversion are scarce. In this work, we studied the chemical composition of SOM on two Robinia pseudoacacia L. plantations and their adjacent croplands in the Loess Plateau using biomarker and nuclear magnetic resonance (NMR) techniques. Experimental data on the molecular composition of SOM showed that the soil microbial biomass carbon content initially decreased and then returned to the original level gradually after afforestation, while the SOM content and stocks increased over time. At the initial stage of afforestation, the content of total solvent extracts did not change significantly but changed slowly over time in the plantations without artificial disturbance. With an increase in restoration time, the concentrations of both the microbial- and plant-derived solvent extracts increased. Moreover, the concentrations of plant-derived solvent extracts were consistently lower than those of microbial-derived solvent extracts. Afforestation also significantly increased the lignin-derived phenol content in the surface soil layer (0-10 cm). However, no obvious change was observed in the lignin-derived phenols of the two adjacent croplands. These results indicate that the accumulation of aboveground litter and underground roots has the strongest effects on the lignin-derived phenol content. In contrast to cropland, the two plantations exhibited a high degree of degradation of lignin-derived phenols in the surface soil, but this remained almost unchanged over time. Moreover, in contrast to 20 years after the establishment of the R. pseudoacacia plantation, the low alkyl/O-alkyl carbon ratio of the 8-year R. pseudoacacia plantation indicated that more easily degradable components accumulated during the initial stage of afforestation. Therefore, the proportion of the unstable carbon pool was relatively high and the SOM content may decline in the early stage of afforestation. These results provide evidence illustrating the detailed changes in the chemical composition of SOM during the ecological restoration process.