Résumé
In a given area, different forms of farming (from small-scale family farming to large-scale enterprises) contribute and respond differently to global challenges such as food insecurity, employment, poverty, climate change and biodiversity. Rapid structural changes are happening (e.g. in land holding size and tenure, use of hired labour, increasing reliance on finance and market integration) but little is known about their impacts. Ongoing agricultural investments have triggered policy debate on the relevance and effects of different business models, and access to knowledge of these is crucial for all stakeholders to be included in policy dialogue. Given the variety and complexity of ongoing transformations, policy debate at national and international levels should be supported by novel approaches for assessing and monitoring this phenomenon. This approach should take into account, among others, for the diverse forms of farming systems; the multiple sectors with which they interact at food chain, territorial and global levels; and impacts on ecosystem services spanning environmental, economic and social dimensions. This paper presents a short review of the literature on agricultural structural change and discusses options to characterize different ongoing patterns of change, not limited to those which took place in developed countries in the second half of the XXth century. It calls a more comprehensive approach to monitor and evaluate these changes in order to improve policies through an assessment of the contributions of different types of farm organizations to sustainable development. In a given territory, and in the relatively long term, transformations can be described at least partly, by the changes in farm types. These structural changes are the result from strategies implemented at farm level to adapt to changing economic and environmental contexts.