Caracterização fisiográfica da bacia hidrográfica do Alto Rio Jamanxim, Pará, Brasil

Abstract

This study presents data on the influence of the land cover type on soil carbon stocks in an Oxisol in southwestern Amazon, Acre, Brazil, under three land cover types: mature forest, pasture and rubber tree plantation. Total soil carbon was calculated using carbon concentration in soil and soil bulk density. Accumulated soil carbon stock up to 1 m depth was greater in mature forest (96 Mg ha-1), followed by pasture (79.7 Mg ha-1) and then by rubber tree plantation (56.3 Mg ha-1); also the greatest carbon accumulation in the surface layers was in pasture. Such results demonstrate that we need not only carbon stocks information by soil type, but also precise information on the land cover classification within a region in order to generate better soil carbon stocks estimations. Also, it is important to notice that mature forest conversion to other land covers can be the source to the atmosphere of about 20 to 40% of the carbon stocked in the soil previously.