@Article{Stahl_etal2017,
author="Stahl, C.
and Fontaine, S.
and Klumpp, K.
and Picon-Cochard, C.
and Grise, M.M.
and Dezecache, C.
and Ponchant, L.
and Freycon, V.
and Blanc, L.
and Bonal, D.
and Burban, B.
and Soussana, J.-F.
and Blanfort, V.",
title="Continuous soil carbon storage of old permanent pastures in Amazonia",
journal="Global Change Biology",
year="2017",
volume="23",
number="8",
pages="3382--3392",
optkeywords="carbon storage",
optkeywords="CN coupling",
optkeywords="deep soil",
optkeywords="mixed-grass pasture",
optkeywords="native forest",
abstract="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 ({\textasciitilde}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 ({\textpm}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 {\textpm} 0.37 and -5.31 {\textpm} 2.08 tC ha-1 yr-1 while the nearby native forest stored -3.31 {\textpm} 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.",
optnote="exported from refbase (http://php.ecofog.gf/refbase/show.php?record=783), last updated on Mon, 29 Jan 2018 09:15:44 -0300",
issn="1365-2486",
doi="10.1111/gcb.13573"
}