MACACC project (ANR-13-AGRO-00)
The impacts of Global Changes and the internalisation of the costs of adaptation are expected to be of such a huge economic importance that they recently raised warnings from institutions such as the World Bank (WorldBank, 2012). Just considering the climatic component, the “Tipping-Point” (or emergence of the temperature increase from the current local climatic oscillations) will likely occur within five to ten years under the tropics and just a few decades later for higher latitudes (Mahlstein et al., 2011; Hawkins and Sutton, 2012; IPCC, 2013). The tropics are vulnerable but count with an immemorial experience in the management of low-input agroecosystems under constraints. They offer to the World an invaluable laboratory for testing adaptation scenarios. Each agroecosystem is defined by a range of temperature and resources beyond which it is no longer viable and should be changed (for crops), or adapted through management practices (for perennial plantations). Some practices can enhance resilience: creating heterogeneity (multi-layers) and diversity (multi-species, several sources of incomes) into the perennial plantations can improve the micro-climate, the effects of facilitation for resource capture (light, water, nutrients), the provision of ecosystem services. Our hypothesis is that some multilayered systems, such as agroforestry, are intrinsically more resilient and could inspire other types of management. MACCAC gathered economists, stakeholders (Professional Organisations + a large panel of producers, > 300), climatologists, ecophysiologists, modelers, around the question of adaptation of their perennial plantations to global changes. Three perennial plantations were selected as case-studies, owing to their economical importance (woody products and coffee), to their origin (2 tropical, Eucalyptus and Coffee-Agroforestry; one in France, Maritime Pine), and to their structure (mono or multi-layer, main crop in upper or under-storey). In accordance with the stakeholders, few realistic “adaptive management scenarios” that could realistically be implemented in the near future were studied. • These adaptive management scenarios were then investigated by the economists of the project to test the “willingness of adoption” of the stakeholders, using choice experiments that aim in particular at evaluating planters’ preferences for a range of incentive mechanisms (Payments for Ecosystem Services, certifications etc); • The climatologists downscaled locally the climatic scenarios for the very next decades and later. These climatic scenarios were then combined with the range of adaptive management scenarios into a biophysical model ( MAESPA + DynACof) running at the scale of forest and agroforest plots, over full cultural cycles. The model was parameterized and verified according to already existing data from actual field experiments, in a large range of conditions for light (climate and density of shade trees), water (rainfall exclusion experiments), nutrient and CO2 availability (Free Air CO2 Enrichment data). The outputs were of the form of profiles of “ecological resilience” per scenario, including a multi-purpose evaluation of the provision of ecosystem services (yield included), for current and future climates; • The “profiles of ecological resilience per scenario” were combined with the “willingness of adoption” and yield finally “a global resilience”, i.e. explicitly including ecological, economical and adoption components of the process of adaptation;
The results on global resilience were then restituted and discussed with stakeholders and ranked according to multi-purpose priorities.The scientific work was evaluated by the stakeholders and the deliverables will be used for outreach, training of planters, students and possibly become tools for decision-building of planters and policy makers.