资源环境科技发展态势分析平台

A combination of high commodity crop prices, rising global food demand, and technological advances has transformed the scale of global crop production. Farming in South America is a prime example, where large-scale cash crops, such as soy, have transformed the land use dynamics at the forest frontier. We evaluate this transformation in sub-Andean South America by estimating crop and forest cover and detecting individual cropland field parcels using Landsat imagery in 5 year intervals over a 24 year period. From 1990 to 2014, cropland expansion onto deforested land was increasingly driven by large fields (>50 ha), whose contribution increased from 32% to 48% (+16% increase), while the contribution of smaller fields (<20 ha) declined from 36% to 26% (-10% decrease). This shift toward large-scale farming replacing cleared land across the region has important implications for food security and biodiversity conservation. Policy efforts will need to target different actors and transcend national borders in order to tackle the changing nature of South American deforestation.