Environmental aspects of molecular composition of humic substances from soils of northeastern European Russia

• Main Authors: Lodygin Evgeny, Vasilevich Roman
• Format: Article in Journal/Newspaper
• Language: English
• Published: Polish Academy of Sciences 2020
• Subjects: arctic; humic acids; fulvic acids; soil; permafrost; tundra; taiga; Geology; QE1-996.5; Arctic; Polar Research; Tundra
• Online Access: https://doi.org/10.24425/ppr.2020.133009; https://doaj.org/article/385d99e447c34fd289b3a550ca08b43b

Data on the molecular structure of humic substances (HSs) of zonal soils for the southern, middle, northern taiga and southern tundra of northeastern European Russia have been obtained. This was accomplished using solid-state 13C nuclear magnetic resonance (13C NMR) technique. The soils under study vary in the point of genesis and degree of hydromorphism. The impact of environmental factors (temperature and humidity) on qualitative and quantitative composition of humic (HAs) and fulvic acids (FAs) has been determined. Excess moisture significantly affects HS accumulation and HS molecular structure: hydromorphic taiga soils accumulate HSs enriched by unoxidized aliphatic fragments, tundra soils – the ones enriched by carbohydrate fragments. Various conditions of soil genesis predefine the specific character of structural and functional parameters of HSs in the southern taiga to southern tundra soils, as is expressed through the increased portion of labile carbohydrate and amino acid fragments and methoxyl groups within the structure of HSs. The tundra humification is characterized by levelling-off of structural and functional parameters of major classes of specific organic compounds of soils – HAs and FAs.