02622naa a2200541 a 450000100080000000500110000800800410001902200460006002400370010610000160014324501670015926000090032652009910033565000130132665000160133965000170135565000250137265000250139765000240142265000260144665000150147265000120148765000120149965000220151165000090153365000220154265000230156465000260158765000160161365300090162965300140163865300240165265300240167665300280170065300250172865300240175365300320177765300260180965300270183565300200186265300190188270000160190170000200191770000160193770000310195370000180198477300780200220964332021-07-02       2019    bl uuuu     u00u1 u    #d  a0103-5053 (impresso) / 1678-4790 (online)7 a10.21577/0103-5053.201801912DOI1 aLEAL, O. A.  aCarbon in physical fractions and organic matter chemical composition of an acrisol after amazon forest burning and conversion into pasture.h[electronic resource]  c2019  aThe aim of this study was to investigate impacts of Amazon Forest (AF) fire and conversion to pasture on carbon accumulation in particle size fractions and organic matter (OM) composition of an Acrisol. Soil samples were collected (0.00-2.00 m depth) in three sites: native AF (NAF); AF under natural regeneration for two years after burning (BAF); 23-years old Brachiaria pasture after AF burning (BRA). Assuming NAF area as reference, BAF and BRA areas showed negative carbon balance when carbon emitted to the atmosphere at AF burning is taken into account. Soil OM aromaticity and hydrophobicity, assessed via 13C nuclear magnetic resonance, in BRA and BAF were similar to that in NAF. Fire and post-fire land use altered the carbon distribution in sand, silt and clay along the soil profile and seem to have affected organo-mineral and OM self-assemblage interactions, since the relation between total soil carbon and carbon in clay was asymptotic in BAF and linear in NAF and BRA.  aAcrisols  aBurnt soils  aCarbon sinks  aEnvironmental impact  aNatural regeneration  aSoil organic matter  aTropical rain forests  aArgissolos  aCarbono  aEstoque  aFloresta Tropical  aFogo  aImpacto Ambiental  aMatéria Orgânica  aRegeneração Natural  aSaturação  aAcre  aAcrisoles  aAmazonia Occidental  aAmazônia Ocidental  aBosque tropical húmedo  aCruzeiro do Sul (AC)  aFazenda Santa Luzia  aMateria orgánica del suelo  aRegeneración natural  aReservorios de carbono  aSuelos quemados  aWestern Amazon1 aDICK, D. P.1 aCOSTA, F. de S.1 aKNICKER, H.1 aCARVALHO JÚNIOR, J. A. de1 aSANTOS, J. C.  tJournal of the Brazilian Chemical Societygv. 30, n. 2, p. 413-424, 2019.