In order to understand AFS multifunctionality and trade-offs between production and ecosystem services that enable sustainable and acceptable management by stakeholders, an integrated approach will be undertaken, which could lead to innovations in the management of these systems and in public policies. The analysis will focus on understanding and characterizing ecosystem services and socio-economic and environmental benefits provided by AFS compared to monocultures. In general, ecosystem services are not independent from each other and their relations are probably non-linear (Power, 2010). Providing a specific service may reduce another one. Then it is referred to as trade-offs. Maximizing provisioning services may lead to some very substantial trade-offs with support and regulation services, as is the case in monocultures. Biodiversity conservation and cultural services are also often considered as being trade-offs with production, which is itself varied and whose diversity and temporality are largely unexplored. However, in the project, we assume that maintaining support and regulation services promote system resilience to climate change.

The comparative analysis will cover a large gradient of AFS structures (from monoculture to complex agroforest) and biophysical, ecological and socio-economic contexts (between HTZ and DTZ and within each of these zones). However, the project will be centred on two perennial crops in the humid tropical zone (HTZ), coffee and cocoa, and on the cerealbased rotation in the dry tropical zone (DTZ). Socio-economic aspects and the stakeholder strategy governing the structure, diversity, dynamic properties and evolution of the AFS will also be taken into account in an approach making explicit the link with the identification of different types of action vectors (technical, training, public policies, market foothold, etc.) at different scales (plot, farm, territory).

Relationships between ecosystem services will be assessed during the AFS life cycle. The different spatial scales will be taken into account by integrating evaluation criteria which are specific to each scale and to the stakeholders involved. Action levers to improve trade-offs between production and services will be identified and formulated in such a way that they may be assessed in this project or in futur programmes as extension of this project. These levers may be technical (e.g. choice and management of species combinations), economic (e.g. payment for a service, a product, such as timber) or public policy related (e.g. type of wood ownership).

This project will include concepts and approaches provided by four WPs, within a single framework shared by the different disciplines, teams and fields:

• WP0: Management and coordination of the project based on a shared conceptual framework

It involves the project WP leaders and leaders of major tasks, and national partners from each country when they are not already included among the task or WP leaders.

• WP1: Characterization of the system composition, structure and dynamics

It involves two tasks, the first will focus on the AFS composition and structure (vertical and horizontal structure and diversity), the second will identify the socio-economic determinants of AFS dynamics.

• WP2: Provisioning services and other ecosystem services in the agroforestry systems, interactions and trade-offs

It is composed of two tasks. The first task will quantify the impact of AFS on ecosystem services from studies of biophysical processes using indicators and models usable under experimental conditions and in smallholder plots. The second task will promote metaanalysis to characterize the relationships between AFS structures and services; it will identify the key factors (biophysical and socioeconomic) determining the establishment of trade-offs between provisioning services and the other ecosystem services within an AFS gradient.

• WP3: Analysis of possible AFS improvements through technical or institutional innovations

This WP is also organized in two tasks which will analyse space of the trade-offs between different services in order to identify, through participatory approaches, the levers for technical and socio-economic action that can move these trade-offs towards a more desirable zone for stakeholders. This approach will be applied at plot and farm scales through task 1 and at territory and farm network scale through task 2.

Based on three major types of AFS distributed among contrasting sites, the SAFSE project, conducted by CIRAD and IRD, will pool multidisciplinary skills and financial and human resources, which will be mutually strengthened around an integrated, multidisciplinary approach with and for the South. This approach has been designed in order to answer a certain number of questions raised by the search on trade-offs between production and other ecosystem services, whilst bringing out some innovative guidelines beyond the case study, in the field of designing and driving these systems, as well as in public policies.