Influence of soil forming factors on the molecular structure of soil organic matter and carbon levels

There is currently an active controversy about the variable influence of the factors involved in the total content and the quality of the soil organic matter (SOM), which translates into its resilience and stability against biodegradation, and importantly on the rates of release of CO2 into the atmo...

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Detalhes bibliográficos
Autores: Jiménez González, Marco Antonio, Álvarez, Ana M., Carral González, Pilar, Almendros, Gonzalo
Formato: artículo
Fecha de publicación:2020
País:España
Recursos:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/696429
Acesso em linha:http://hdl.handle.net/10486/696429
https://dx.doi.org/10.1016/j.catena.2020.104501
Access Level:acceso abierto
Palavra-chave:Analytical pyrolysis
Carbon sequestration
Discriminant analysis
Soil organic matter
Geología
Descrição
Resumo:There is currently an active controversy about the variable influence of the factors involved in the total content and the quality of the soil organic matter (SOM), which translates into its resilience and stability against biodegradation, and importantly on the rates of release of CO2 into the atmosphere. The aim of this work is to study the molecular composition of SOM in contrasting environments in order to evaluate the extent to which such conditions may affect SOM characteristics in addition to the levels of soil organic C (SOC). Up to 33 soils from different environmental scenarios of Spain were analysed by pyrolysis combined with gas chromatography mass spectrometry (Py-GC/MS). The 193 major pyrolysis compounds released from the soils were included in a chemostatistical study based in discriminant analysis to assess the impact of classical soil forming factors (i.e., climate, vegetation and geological substrate) in SOM content and composition. Improved van Krevelen diagrams were used to facilitate the recognition of different patterns in SOM composition dependent on soil forming factors. The results showed that the molecular composition of SOM varies systematically according to environmental factors, with a decreasing influence in the order: climate > vegetation > geological substrate. In addition, the total levels of SOM were also different depending on the environmental scenarios on these soils, suggesting both qualitative and quantitative control of soil C sequestration