植物生态学报 ›› 2019, Vol. 43 ›› Issue (4): 284-295.doi: 10.17521/cjpe.2018.0213

• 综述 • 上一篇    下一篇

中性糖在土壤中的来源与分布特征

刘程竹1,2,贾娟1,2,戴国华1,马田1,2,冯晓娟1,2,*()   

  1. 1 中国科学院植物研究所植被与环境变化国家重点实验室, 北京 100093
    2 中国科学院大学, 北京 100049
  • 收稿日期:2018-08-27 修回日期:2019-04-18 出版日期:2019-04-20 发布日期:2019-08-29
  • 通讯作者: 冯晓娟 ORCID:0000-0002-0443-0628 E-mail:xfeng@ibcas.ac.cn
  • 基金资助:
    国家重点基础研究发展计划(973计划)(2015CB954201);国家自然科学基金(41773067);国家自然科学基金(41422304);中国科学院对外合作重点项目(151111KYSB20160014)

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 E-mail:xfeng@ibcas.ac.cn
  • 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)

摘要:

糖类(即碳水化合物)是土壤有机质的重要组成部分, 经生物化学降解形成不同结构的单糖。土壤中的中性单糖也叫中性糖, 主要包括木糖、核糖、阿拉伯糖、葡萄糖、半乳糖、甘露糖、岩藻糖和鼠李糖。其中, 植物来源的糖主要为五碳糖, 如木糖和阿拉伯糖; 微生物来源的糖主要包括半乳糖、甘露糖、岩藻糖、鼠李糖等六碳糖。研究中常利用六碳糖和五碳糖的比例指示微生物和植物对土壤有机碳的相对贡献。中性糖是微生物重要的碳源和能量来源, 在团聚体的形成过程中扮演着重要角色。该文整合了近30年土壤中性糖的研究进展, 对比了提取中性糖的常用方法, 分析了不同土地利用类型和不同土壤组分中中性糖的含量、来源和周转特征, 综述了影响中性糖含量和分布的主要环境因素。结果表明, 中性糖在耕地土壤中的绝对含量和相对含量均显著低于针叶林、阔叶林、草地和灌丛4种土地利用类型。(半乳糖+甘露糖)/(阿拉伯糖+木糖)(GM/AX)在不同土地利用间差异不显著, 而(鼠李糖+岩藻糖)/(阿拉伯糖+木糖)(RF/AX)则表明草地土壤中的微生物来源的中性糖含量高于针叶林和耕地。不同密度的土壤组分中, 轻质组分中中性糖的含量比重质组分高, 重质组分中微生物来源的中性糖较多; 就不同粒径(或团聚体)而言, 黏粒(或微团聚体)中微生物来源的中性糖含量更丰富。有关影响土壤中性糖含量和分布的因素的研究, 目前主要集中在人为活动(如耕种和放牧等), 而有关温度、降水等自然环境因素影响的研究较少。

关键词: 土壤, 中性糖, 来源, 分布特征, 影响因素

Abstract:
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