The purpose of this thesis is to examine the nature and scope of the linkages between the resource environments, livelihoods and food security of households and individuals. These are analyzed using the livelihood systems framework with the biophysical environment as the entry point. The biophysical and socio-economic environments are investigated as the conditioning and influencing factors that help define the relationships along the production-consumption continuum. The context is spatial, in this case that of fragile areas, where most of the poor and food insecure live and work. Food security is viewed in a three-dimensional perspective: food availability, food access, and food adequacy. Food security should be an integrative concept and most pressing because, arguably, none other would shake the global community with 840 million to 1.3 billion people languishing in the dire misery of hunger.