Biochemically altered charcoal residues as an important source of soil organic matter in subsoils of fire-affected subtropical regions

9 páginas.-- 3 figuras.-- 6 tablas.-- 50 referencias

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Main Authors: Velasco Molina, Marta, Berns, Anne E., Macías, Felipe, Knicker, Heike
Format: artículo biblioteca
Language:English
Published: Elsevier 2016-01-15
Subjects:Biochemical C cycling, Fire as a soil forming factor, Humification of charcoal, NMR spectroscopy, Oxidized PyOM, Aromatic compounds, Aromatization, Biodegradation, Biogeochemistry, Biological materials, Charcoal,
Online Access:http://hdl.handle.net/10261/121596
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record_format koha
institution IRNAS ES
collection DSpace
country España
countrycode ES
component Bibliográfico
access En linea
databasecode dig-irnas-es
tag biblioteca
region Europa del Sur
libraryname Biblioteca del IRNAS España
language English
topic Biochemical C cycling
Fire as a soil forming factor
Humification of charcoal
NMR spectroscopy
Oxidized PyOM
Aromatic compounds
Aromatization
Biodegradation
Biogeochemistry
Biological materials
Charcoal
Biochemical C cycling
Fire as a soil forming factor
Humification of charcoal
NMR spectroscopy
Oxidized PyOM
Aromatic compounds
Aromatization
Biodegradation
Biogeochemistry
Biological materials
Charcoal
spellingShingle Biochemical C cycling
Fire as a soil forming factor
Humification of charcoal
NMR spectroscopy
Oxidized PyOM
Aromatic compounds
Aromatization
Biodegradation
Biogeochemistry
Biological materials
Charcoal
Biochemical C cycling
Fire as a soil forming factor
Humification of charcoal
NMR spectroscopy
Oxidized PyOM
Aromatic compounds
Aromatization
Biodegradation
Biogeochemistry
Biological materials
Charcoal
Velasco Molina, Marta
Berns, Anne E.
Macías, Felipe
Knicker, Heike
Biochemically altered charcoal residues as an important source of soil organic matter in subsoils of fire-affected subtropical regions
description 9 páginas.-- 3 figuras.-- 6 tablas.-- 50 referencias
format artículo
topic_facet Biochemical C cycling
Fire as a soil forming factor
Humification of charcoal
NMR spectroscopy
Oxidized PyOM
Aromatic compounds
Aromatization
Biodegradation
Biogeochemistry
Biological materials
Charcoal
author Velasco Molina, Marta
Berns, Anne E.
Macías, Felipe
Knicker, Heike
author_facet Velasco Molina, Marta
Berns, Anne E.
Macías, Felipe
Knicker, Heike
author_sort Velasco Molina, Marta
title Biochemically altered charcoal residues as an important source of soil organic matter in subsoils of fire-affected subtropical regions
title_short Biochemically altered charcoal residues as an important source of soil organic matter in subsoils of fire-affected subtropical regions
title_full Biochemically altered charcoal residues as an important source of soil organic matter in subsoils of fire-affected subtropical regions
title_fullStr Biochemically altered charcoal residues as an important source of soil organic matter in subsoils of fire-affected subtropical regions
title_full_unstemmed Biochemically altered charcoal residues as an important source of soil organic matter in subsoils of fire-affected subtropical regions
title_sort biochemically altered charcoal residues as an important source of soil organic matter in subsoils of fire-affected subtropical regions
publisher Elsevier
publishDate 2016-01-15
url http://hdl.handle.net/10261/121596
work_keys_str_mv AT velascomolinamarta biochemicallyalteredcharcoalresiduesasanimportantsourceofsoilorganicmatterinsubsoilsoffireaffectedsubtropicalregions
AT bernsannee biochemicallyalteredcharcoalresiduesasanimportantsourceofsoilorganicmatterinsubsoilsoffireaffectedsubtropicalregions
AT maciasfelipe biochemicallyalteredcharcoalresiduesasanimportantsourceofsoilorganicmatterinsubsoilsoffireaffectedsubtropicalregions
AT knickerheike biochemicallyalteredcharcoalresiduesasanimportantsourceofsoilorganicmatterinsubsoilsoffireaffectedsubtropicalregions
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spelling dig-irnas-es-10261-1215962018-09-12T11:46:54Z Biochemically altered charcoal residues as an important source of soil organic matter in subsoils of fire-affected subtropical regions Velasco Molina, Marta Berns, Anne E. Macías, Felipe Knicker, Heike Biochemical C cycling Fire as a soil forming factor Humification of charcoal NMR spectroscopy Oxidized PyOM Aromatic compounds Aromatization Biodegradation Biogeochemistry Biological materials Charcoal 9 páginas.-- 3 figuras.-- 6 tablas.-- 50 referencias Although climatic conditions of subtropical regions support fast biochemical degradation of soil organic matter (SOM), some of their soils reveal dark umbric horizons with considerably high organic C contents. Since such soils can reach a depth of several meters a better understanding of the processes involved in the humification of its SOM is essential for an improved elucidation of the impact of the hot and humid conditions of subtropical regions on global C cycling. Therefore, the SOM of three Umbric Ferralsols from Brazil was characterized for its quantity and chemical composition as a function of soil depth. Solid-state 13C nuclear magnetic resonance (NMR) spectra revealed an increase of the aromaticity with soil depth to exceptionally high values between 40 and 70% of the SOM. Chemical oxidation of the SOM with acid potassium dichromate confirmed that a major part of this C group is attributable to pyrogenic organic matter (PyOM). High carboxyl-C contents between 13 and 21% of the total organic C in the subsoils showed that their PyOM is strongly oxidized, most likely due to previous intense biochemical reworking. Since the latter improves the water solubility of the formerly hydrophobic charcoal residues, such oxidized PyOM can be transported with the soil solution into deeper soil horizons. As indicated by the pattern of the 13C NMR spectra and the high C contents of the subsoil, the partially degraded PyOM seems to have lost its attractiveness to microbial attack with ongoing downward movement and accumulation. Correlating parameters of organic matter with those of soil mineralogy suggested that in addition to stabilization by the mineral phase other mechanisms must have contributed to the persistence of PyOM in the studied soils. Considering that in soils, microbial degradation of aromatic structures is mainly performed by lignolytic and aerobic organisms, we suggest that increasing oxygen depletion and unfavorable living conditions in the deeper soil regions decreased the activity of those organisms. This enhanced the biochemical recalcitrance of the aromatic PyOM whereas non-pyrogenic SOM was still subjected to degradation although most likely at a slower rate. As a consequence, the selective preservation of PyOM shifted not only the quality of the subsoil SOM toward higher aromaticity but also increased its quantity. Based on our results, we concluded that downward translocation of partially degraded PyOM and its subsequent accumulation represent important processes in soil systems which are frequently affected by fires. © 2015 Elsevier B.V. The authors thank Pablo Vidal-Torrado, Márcia Calegari and Flávio Marques of the ESALQ of the Universidade de São Paulo (Brazil) for providing the soil samples. The Lehrstuhl für Bodenkunde of the Technische Universität München (Germany) and the Institute of Bioand Geosciences, Agrosphere (IBG-3) of the Forschungszentrum Jülich (Germany) are gratefully acknowledged for hosting the first author and giving her access to their NMR facilities. Comparably, the Centro de Investigación, Tecnología e Innovación of the Universidad de Sevilla (Spain) is thanked for allowing the use of their solid-state NMR instrument. The European Science Foundation (EG/3696) is acknowledged for the travel grant supplied from the activity entitled “Natural molecular structures as drivers and tracers of terrestrial C fluxes (MOLTER)” given to the first author. Peer reviewed 2015-09-03T05:40:50Z 2015-09-03T05:40:50Z 2016-01-15 artículo http://purl.org/coar/resource_type/c_6501 Geoderma 262 (12065): 62-70 (2016) 0016-7061 http://hdl.handle.net/10261/121596 10.1016/j.geoderma.2015.08.016 en http://dx.doi.org/10.1016/j.geoderma.2015.08.016 Sí none Elsevier