TY  - JOUR
AU  - Stahl, C.
AU  - Freycon, V.
AU  - Fontaine, S.
AU  - Dezecache, C.
AU  - Ponchant, L.
AU  - Picon-Cochard, C.
AU  - Klumpp, K.
AU  - Soussana, J.-F.
AU  - Blanfort, V.
PY  - 2016//
TI  - Soil carbon stocks after conversion of Amazonian tropical forest to grazed pasture: importance of deep soil layers
JO  - Regional Environmental Change
SP  - 2059
EP  - 2069
VL  - 16
IS  - 7
N2  - Recent studies suggest that carbon (C) is stored in the topsoil of pastures established after deforestation. However, little is known about the long-term capacity of tropical pastures to sequester C in different soil layers after deforestation. Deep soil layers are generally not taken into consideration or are underestimated when C storage is calculated. Here we show that in French Guiana, the C stored in the deep soil layers contributes significantly to C stocks down to a depth of 100 cm and that C is sequestered in recalcitrant soil organic matter in the soil below a depth of 20 cm. The contribution of the 50–100 cm soil layer increased from 22 to 31 % with the age of the pasture. We show that long-term C sequestration in C4 tropical pastures is linked to the development of C3 species (legumes and shrubs), which increase both inputs of N into the ecosystem and the C:N ratio of soil organic matter. The deep soil under old pastures contained more C3 carbon than the native forest. If C sequestration in the deep soil is taken into account, our results suggest that the soil C stock in pastures in Amazonia would be higher with sustainable pasture management, in particular by promoting the development of legumes already in place and by introducing new species.
SN  - 1436-378x
UR  - http://dx.doi.org/10.1007/s10113-016-0936-0
N1  - exported from refbase (http://php.ecofog.gf/refbase/show.php?record=721), last updated on Mon, 29 Jan 2018 09:15:53 -0300
ID  - Stahl_etal2016
ER  -