Carbon and nitrogen stocks in the soils of the Amazon Region

Soil nitrogen and organic carbon stocks, to a depth of 0.3 m and 1 m respectively, were determined for the Amazon Region using the soil and terrain (SOTER-LAC) database for Latin America and the Caribbean. Mean carbon densities, to a depth of 1 m, range from 4.0 kg m(-2) for coarse textured Arenosols to 72.4 kg m(-1) for the poorly drained Histosols. Mean carbon density for the mineral soils, excluding Arenosols and Andosols (30.5 kg C m(-2)), is 9.8 kg m(-2). In total, the top 1 m holds 66.9 Pg C and 6.9 Pg N. About 52% of this carbon pool is held in the top 0.3 m of the soil, the layer which is most prone to changes upon land use conversion and deforestation. (C) 1999 Elsevier Science B.V. All rights reserved.