Quaternary Research · 2007 · 35 citations · 28 references
AgricultureEarth SciencesSoil SciencesSoil ChemistrySoil Organic MatterSoil ScienceBiomass Burning EmissionsMineral-associated Organic CarbonSoil Carbon ChemistrySoil Carbon FractionationSoil GeochemistrySoil PollutionBlack CarbonCarbon Isotopes In SoilColluvial SoilsFire-induced Soil Carbon LossFire-produced Organic CompoundsPolycyclic Aromatic HydrocarbonsSoil Organic CarbonSoil Organic Carbon Fractions
Analytical pyrolysis-GC/MS and solid-state 13 C NMR (nuclear magnetic resonance) were applied to the NaOH-extractable organic matter fraction of a colluvial soil from Galicia (NW Spain) that represents more than 8500 yr of accumulation. While molecular indicators of vegetation change were looked for, it seemed likely that any such signal was disturbed by the intense fire regime of the area. This conclusion was drawn from (1) the presence of three charcoal layers, (2) the high proportion of aryl C in NMR spectra (non-quantitative) and (3) the prevalence of benzenes and polycyclic aromatic hydrocarbons (PAHs) in the chromatograms (38±6% of total identified peak area), also in charcoal-poor samples. If this conclusion is accurate, the area has been subjected to burning episodes for at least 8000 yr. Additionally, the results indicate that biomass burning residues (black carbon; BC) may become NaOH extractable after long periods of degradation in mineral soil. These results add to our knowledge of the long-term fate of BC in soil, which is a potential agent in the global C cycle.
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Cellulose char structure: a combined analytical Py-GC-MS, FTIR, and NMR study
Ivana Pastorova, Robert E. Botto, Peter W. Arisz et al. · Carbohydrate Research · 1994 · 419 citations