Chin J Plant Ecol ›› 2019, Vol. 43 ›› Issue (4): 284-295.DOI: 10.17521/cjpe.2018.0213

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Origin and distribution of neutral sugars in soils

LIU Cheng-Zhu1,2,JIA Juan1,2,DAI Guo-Hua1,MA Tian1,2,FENG Xiao-Juan1,2,*()   

  1. 1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2018-08-27 Revised:2019-04-18 Online:2019-04-20 Published:2019-08-29
  • Contact: FENG Xiao-Juan ORCID:0000-0002-0443-0628
  • Supported by:
    Supported by the Chinese National Key Development Program for Basic Research(2015CB954201);the National Natural Science Foundation of China(41773067);the National Natural Science Foundation of China(41422304);the International Partnership Program of Chinese Academy of Sciences(151111KYSB20160014)


Carbohydrates are important components of soil organic matter, which can be decomposed to different types of monosaccharides. Neutral monosaccharides in the soil are also called neutral sugars, including xylose, ribose, arabinose, glucose, galactose, mannose, fucose and rhamnose. Among them, plant-derived sugars mainly include pentoses, such as xylose and arabinose, while microbial-derived sugars mainly consist of hexoses including galactose, mannose, fucose and rhamnose. Generally, the ratios of hexoses to pentoses are used to evaluate the contribution of microbial- versus plant-derived sugars. Neutral sugars are the main carbon and energy resources for soil microorganisms and play a vital role in aggregates formation. In this study, we review studies about neutral sugars in soils over the past 30 years and compare different methods for neutral sugar analysis. Furthermore, we compare the distribution patterns and turnover of soil neutral sugars across diverse land-use regimes, different soil density and particle size fractions and their influencing factors. The lowest neutral sugar content is found in arable soils compared with other four land-use types (coniferous forests, deciduous forests, shrublands and grasslands) in terms of absolute and relative contents. No significant difference is observed for the (galactose + mannose)/‍(arabinose + xylose)(GM/AX) ratios across the five land-use regimes. Nevertheless, the ratio of (rhamnose + fucose)/(arabinose + xylose)(RF/AX) indicates that microbially derived neutral sugars are more abundant in the soils of grasslands than coniferous forests or farmlands. The heavy fraction is characterized by an enrichment of microbial neutral sugars but a lower content of total neutral sugars compared to the light fraction. Concerning the distribution of neutral sugars across different soil size fractions (or aggregates), the microbial-derived neutral sugars are more abundant in the clay fraction (or microaggregates). As for the factors affecting neutral sugar content and distribution, many studies have focused on the human disturbances like agriculture and grazing, while the influence of environmental factors such as temperature, precipitation is poorly investigated.

Key words: soil, neutral sugars, origin, distribution, influencing factor