The effects of population and land cover change on food security in Latin America from 1961 - 2001

Introduction Unprecedented population growth accompanied equally unprecedented land use and land cover changes in Latin America during the second half of the twentieth century, affecting the food security of thousands of agriculturally based communities. The more than doubling of the population of Latin America was accompanied by rural migration to urban areas and extensification, or expansion, of agricultural land at the expense of forest and natural environments (Carr, Lopez, and Bilsborrow 2009). We have previously found that when these processes were examined at a country scale, both Malthusian and Boserupian demographic factors were important in explaining rural out-migration and forest cover decreases (Carr, Lopez, and Bilsborrow 2009). Our results supported Bilsborrow's application of the theory of multiphasic response: that these two different types of drivers can be simultaneously present, acting influentially at different spatial and demographic levels (Carr, Lopez, and Bilsborrow 2009). The process of agricultural extensification has obvious natural limits, as the remaining high-quality arable land is increasingly exploited in response to growing populations or market demands. In addition, much of the world's undeveloped arable land is either protected by laws or is of poor soil or topographic quality (World Bank 1995). As extensification becomes more difficult the only viable option for continued increases in food production is agricultural intensification. Of course, the process is not linear and both extensification and intensification occur in areas simultaneously. In addition, a causal relationship between these processes is far from certain, with some