TY  - JOUR
AU  - Stahl, C.
AU  - Fontaine, S.
AU  - Klumpp, K.
AU  - Picon-Cochard, C.
AU  - Grise, M.M.
AU  - Dezecache, C.
AU  - Ponchant, L.
AU  - Freycon, V.
AU  - Blanc, L.
AU  - Bonal, D.
AU  - Burban, B.
AU  - Soussana, J.-F.
AU  - Blanfort, V.
PY  - 2017//
TI  - Continuous soil carbon storage of old permanent pastures in Amazonia
T2  - Glob Change Biol
JO  - Global Change Biology
SP  - 3382
EP  - 3392
VL  - 23
IS  - 8
KW  - carbon storage
KW  - CN coupling
KW  - deep soil
KW  - mixed-grass pasture
KW  - native forest
N2  - Amazonian forests continuously accumulate carbon (C) in biomass and in soil, representing a carbon sink of 0.42–0.65 GtC yr−1. In recent decades, more than 15% of Amazonian forests have been converted into pastures, resulting in net C emissions (~200 tC ha−1) due to biomass burning and litter mineralization in the first years after deforestation. However, little is known about the capacity of tropical pastures to restore a C sink. Our study shows in French Amazonia that the C storage observed in native forest can be partly restored in old (≥24 year) tropical pastures managed with a low stocking rate (±1 LSU ha−1) and without the use of fire since their establishment. A unique combination of a large chronosequence study and eddy covariance measurements showed that pastures stored between −1.27 ± 0.37 and −5.31 ± 2.08 tC ha−1 yr−1 while the nearby native forest stored −3.31 ± 0.44 tC ha−1 yr−1. This carbon is mainly sequestered in the humus of deep soil layers (20–100 cm), whereas no C storage was observed in the 0- to 20-cm layer. C storage in C4 tropical pasture is associated with the installation and development of C3 species, which increase either the input of N to the ecosystem or the C:N ratio of soil organic matter. Efforts to curb deforestation remain an obvious priority to preserve forest C stocks and biodiversity. However, our results show that if sustainable management is applied in tropical pastures coming from deforestation (avoiding fires and overgrazing, using a grazing rotation plan and a mixture of C3 and C4 species), they can ensure a continuous C storage, thereby adding to the current C sink of Amazonian forests.
SN  - 1365-2486
UR  - http://dx.doi.org/10.1111/gcb.13573
N1  - exported from refbase (http://php.ecofog.gf/refbase/show.php?record=783), last updated on Mon, 29 Jan 2018 09:15:44 -0300
ID  - Stahl_etal2017
ER  -