Greenhouse gas emissions

“Best bet” Land-use Systems

Country reports

Alternatives to Slash-and-Burn in Brazil

Global Environmental Concerns

Unique id: IDA3SG3B

Source file: D:\Projects\ASB\ASB Country and Thematic reports\Brazil country report\ASB Brazil Summary Report.xml

Authors: S. Vosti, C. L. Carpentier, J. Witcover, . Carvalho dos Santos, E. Muñoz Braz, J. Ferreira Valentim, S. J. de Magalhães de Oliveira, C. Palm, F. de Souza Moreira, A. Cattaneo, A. Gillison, A. Mansur Mendes, V. Rodrigues, T. C. de Araújo Gomes, M. V. Neves d’Oliveira, E. do Amaral, S. Fujisaka, C. Castilla, T. Tomich, D. Bignell, D. Gonçalves Cordeiro, A. Hermes Vieira, R.S. Correira da Costa, M. Faminow, M. Locatelli, M. Swift, S. Weise, M. van Noordwijk, N. Sampaio, I. L. Franke, H. J. Borges de Araujo, L. M. Rossi, E. Barros, B. Feigl, S.P. Huang, J. Cares, C. Pinho de Sá, . Carneiro, P. Woomer

--------------------------------------------------------------------------

A second goal of the ASB climate change work during Phase II was to sample and compare trace gas fluxes from the various traditional and alternative LUS at the benchmark sites and to identify the soil-related, land-management and other factors influencing these fluxes. In addition to CO₂, deforestation and subsequent land uses emit methane and nitrous oxide, two other greenhouse gases. Methane is the second most important greenhouse gas in terms of amounts and effects in the atmosphere. Most well drained upland soils serve as a net sink of methane through the consumption of methane by methanotrophic micro-organisms in the soil. However, there is increasing evidence that the size of this sink diminishes when land is converted from forest to other uses. For example, conversion to pastures in the humid tropics can result in a net emission of methane from the soil through the process of methanogenesis (Steudler et al, 1996; Keller et al, 1997).