ABSTRACT
Global warming incites the global community and especially scientists to deepen their studies about the global carbon cycle. Rising levels of atmospheric CO2 have led to attention of C stocks (CS) in main terrestrial compartments, mainly soils and phytomass. The world’s mineral soils represent a large reservoir of C, with estimations ranging from 1,115 to 2,200 Pg C (1 Pg = 1,015 g, or 1 Pg = 1 billion tons) in the first meter (Post et al., 1982; Batjes, 1996). Plant biomass is estimated to range between 560 and 835 Pg C (Whittaker and Likens, 1975; Bouwman, 1990). Tropical forest ecosystems would account for 20 to 25 percent of the carbon contained in soil and vegetation (Brown and Lugo, 1982; Dixon et al., 1994). Volkoff and Bernoux (Chapter 1) presented a regionalization of Latin America based on soil and environmental data: the complex landscape of Latin America is divided into 13 soil ecoregions in order to significantly reduce the spatial variability. The objectives of this chapter are (1) to assess the original soil C stocks of Latin America for the different countries and soil ecoregions, and (2) to estimate the part of this total that could have been impacted by past land-use activities.
