Climatic and Socioeconomic Determinants of the Supply and Demand of Net Primary Production in sub-Saharan Drylands

Abstract:

Around two-thirds of Africa’s inhabitants live in drylands and rely on multifaceted livelihoods involving rain-fed agriculture, cash crops, pastoralism, and livestock production. A large portion of dryland sub-Saharan Africa is under the influence of global climatic teleconnections that produces variability in the Earth’s climate. Areas where the vegetation has a strong response to climatic variability clearly exhibit the relationship between human well-being and the climate system. We define NPP supply as the annual amount of carbon that plants remove from the atmosphere through photosynthesis and store as biomass, and NPP demand is the annual amount of carbon required for food, feed and fuel and it drives land use changes such as the expansion of cropland, wood fuel extraction and pasture creation. In this poster, we present preliminary evidence to show that global climatic teleconnections regulate the NPP supply in Africa, while NPP demand increase as a function of demographic growth. Our results point to a scenario whereby the demand for NPP could outpace available supply. Increased climatic variability and extreme events could potentialy tilt this balance further by reducing NPP supply through intense droughts and floods.