Agricultural land-use change in Brazilian Amazoˆnia between 1980 and 1995: Evidence from integrated satellite and census data

As cropland and pasture have replaced forest and cerrado in Brazilian Amazoˆnia, concern has mounted over the effects of changing the biogeochemical and hydrological properties of one of the world's great storehouses of biomass and biodiversity. Although much recent effort has focused on the location, effects, and causes of deforestation and cerrado conversion, much less is known about the basin-wide spatial distribution and density of the land use following conversion for crops or pasture.In this paper, we use census and satellite records to develop maps of the distribution and abundance of major agricultural land uses across 4.5×108 ha of Brazilian Amazoˆnia in 1980 and 1995. Results indicate an overall expansion of 7.0×106 ha in total agricultural area in Brazilian Amazoˆnia between 1980 and 1995. The net change during this period is estimated for three different land-use types: croplands (an increase of 0.8×106 ha), natural pastures (a decrease of 8.4×106 ha), and planted pastures (an increase of 14.7×106 ha). These estimates, the first spatially explicit quantifications of agricultural land-use activities in 1980 and 1995 across Brazilian Amazoˆnia, are shown to be consistent with the results of applying a land use change and secondary regrowth model to published deforestation rates for the period.The resulting time slices, presented for each land-use category at 5-min (∼9 km) spatial resolution, allow for the quantification of land-use changes in this region for biogeochemical, demographic and economic models. Several foci of agricultural change existed within Brazilian Amazoˆnia during this period: in the state of Para´, cropland was lost and planted pasture increased markedly; in Mato Grosso, both cropland and planted pasture increased; in Rondoˆnia, planted pasture replacing forest was the primary route to agricultural expansion. [Copyright &y& Elsevier]