s:1704:"%T The effects of forest conversion on annual crops and pastures: Estimates of carbon emissions and plant species loss in a Brazilian Amazon colony %A Fujisaka, S., Castilla, C., Escobar, G., Rodrigues, V., Veneklaas, E., Thomas, R., Fisher, M. %X The municipality of Theobroma in Rondonia, Brazil, covers 2165 km2, of which 43% was deforested by 1993. Between 1973 and 1993, the national government continued to improve highway BR364 connecting the area to Brazil's south-central region and established a colony in Theobroma. During this period, 98% of the deforestation occurred. Some 1800 settler families continue to convert forest into pasture in a system based on the slash-and-burn agriculture and dual-purpose cattle production. Trends in carbon emissions and plant species losses during the 20-year history of Theobroma were analyzed by combining observed shifts in land-use types with estimates for the carbon stocks and plant species richness of each of these types. Carbon stocks declined from about 200 t ha1 in the forest to 28 t ha1 in the pasture and of 326 plant species encountered in the forest, only 20 remained in pastures (along with 66 species not found in forests). The effects of converting more than 93000 ha of forest into other uses over 20 years include approximate losses of 14 million tons of C to the atmosphere and substantial losses of plant species. Land use alternatives that would store more C include agroforestry and – given the strong incentives for settlers to convert lands into pasture –improving pasture management or developing silvopastoral systems. Plant species conservation may be improved with proposed ways to add private value to the forest. ";