Evaluation of the Agro-Ecological Zone methods for the study of climate change with micro farming decisions in sub-Saharan Africa.

摘要

This paper evaluates the Agro-Ecological Zone (AEZ) methods for understanding agriculture and measuring the impacts of climate change on agriculture with the observed farming decisions in sub-Saharan Africa. The Agro-Ecological Zone (AEZ) method is explained using the concept of the Length of Growing Period (LGP) and the AEZ classification of the African continent. Farmers' decisions are obtained from the World Bank household surveys of around 8000 farms across 9 sub-Saharan countries. The AEZ results are compared with the observed behavioral decisions of the farmers as well as future predictions of behaviors. Observed choices of agricultural systems, crop net revenues, distributions of livestock species, and grain yields are compared with the AEZ classification. This paper finds that the AEZ/LGP classification identifies the land's suitability for crop farming well, but is a poor indicator of livestock systems, both specialized and diversified. It also does a poor job of identifying nonmajor grains such as forest activities. Besides these identification issues, adaptive decisions such as diversification and risk management are difficult to capture by the AEZ methods. These problems become evident when the AEZ method is applied to measure the impacts of future climate changes since the shifts of farming behaviors are hard to measure. Future research is needed to improve the classification of agro eco-systems and to develop an improved integrated analysis of ecological sciences and economics.