摘要：We argue that reading the local agricultural landscape is a prerequisite to understanding the plausible local impacts of external drivers for change, such as the introduction of new crops and technologies. Initially driven by a desire to understand the potential for small-scale farmers to produce jatropha biodiesel in a sustainable way, we started to examine how farmers related to trees in different parts of the agricultural landscape. This provided us with insights into small-scale processes of land enclosure and conversion, which indicate that agricultural intensification is taking place. We learned that although the landscape could in theory accommodate a lot of jatropha hedges around existing (maize dominated) arable land, farmers were only creating hedges around new fields, carved out in the grazing commons. Already well established within the settlement, jatropha can produce a range of different ecosystem services. However, our case study suggests that scalability is problematic: cultural ecosystem services can be provided at very limited levels of production; supporting ecosystem services require a certain scaling up of production; and provisioning ecosystem services, like biofuels, would require production to be increased well beyond any synergies with ongoing tree plantings or land conversion processes.
关键词：Africa; agricultural intensification; biofuels; live fence; marginal land
