Agriculture, ecosystems and environment: Long-term soil carbon loss and accumulation in a catchment following the conversion of forest to arable land in northern Laos

• ភាសាអង់គ្លេស

• Agriculture
• Ecosystems
• Environment and natural resources

• ឡាវ

• Luangprabang

© 2013 Elsevier B.V

Corresponding author. Tel.: +33 1 44 27 72 82; fax: +33 1 44 27 41 64. E-mail address: sylvain.huon@upmc.fr (S. Huon). et al., 2002; Wezel et al., 2002 ). Moreover, eroded carbon, once in the river network and subject to mineralization, may contribute to greenhouse gas emissions ( Lal, 2003 ). Soil erosion studies con- ducted from plot to hill slope scales are frequently used to assess soil organic carbon detachment and transport by overland flow ( e.g. , Bellanger et al., 2004 ) but it remains difficult to upscale these results to the catchment level because they are often subject to threshold effects ( Lugo and Brown, 1993; Turkelboom et al., 2008 ), involve different processes ( e.g. , Poesen et al., 1996 ) and do not account for deposition along slopes and valley bottoms ( Chaplot and Poesen, 2012 ). The catchment unit appears to be an appropriate scale because it integrates topography and other land characteris- tics as well as how cultivation responds to them. Moreover, this unit is often repeated in the landscape and may be used for out scaling. In Southeast Asia smallholders who practice shifting cultivation clear the forest predominantly on sloping land. Although slash-and-burn 0167-8809/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.agee.2013.02.007