Trade-offs between crop intensification and ecosystem services: the role of agroforestry in cocoa cultivation

Research published in this special issue on cocoa agroforestry illustrates the multifunctional role of shade trees for sustaining cocoa production and improving farmers¿ livelihoods, and addresses tradeoffs between higher cocoa yield and the provision of ecosystem services to local households and global society. Indeed, the use of diverse shade in cocoa cultivation is threatened by a new drive towards crop intensification. The removal of shade trees diminishes smallholders¿ ability to adapt to global change driven by demographic pressure, food insecurity, cocoa price volatility and climate change. Some forms of crop intensification may reduce ecological resilience of cocoa production systems, making adaptation strategies, combining shade trees with innovative management practices, essential for sustaining cocoa yield. Managing trade-offs between yield and environmental services at the cocoa plot and landscape scales requires a multi-disciplinary approach to identify key management options that goes beyond the artificially polarized debates around intensified versus traditional agroforestry practices, or more generally, land-sparing versus land-sharing strategies. The global challenge facing the cocoa sector today is how to increase cocoa production to meet growing demand, without expanding the area under cocoa. This means finding sustainable ways to maintain cocoa production within today¿s producing regions, particularly West Africa, through a series of technical innovations geared towards smallholders. Inappropriate intensification may result in heavy deforestation on new pioneer fronts, such as the Congo basin, and existing cocoa being replaced either by other agricultural commodities, or by less resilient and less environmentally friendly production practices. (Résumé d'auteur

Améliorer les systèmes agroforestiers en zone tropicale humide : cas des cacaoyers et des caféiers [fiches de compétences forêts SIA 2011]

En zone tropicale humide, les systèmes agroforestiers (SAF) associent aux arbres forestiers des cultures pérennes (café, cacao, fruitiers...), ou encore des cultures vivrières ou de l'élevage. Ces SAF sont issus d'une part, de forêts naturelles dans lesquelles une partie de la végétation d'origine a été substituée par des arbres producteurs ou des cultures, d'autre part, de la replantation d'arbres après défriche de la forêt pour des cultures vivrières. Ces modes d'exploitation aboutissent après quelques années à un système complexe de productions multiples. Dans un contexte de diminution des terres disponibles, de pression démographique rurale, de crise alimentaire, de limites atteintes par l'intensification conventionnelle de l'agriculture et de changement climatique, l'agroforesterie offre des perspectives intéressantes. Améliorer la gestion des systèmes agroforestiers, assurer leur durabilité environnementale, technique et sociale représente un enjeu important pour la recherche et le développement. (Résumé d'auteur

Coffee agroforestry in Kodagu, western ghats, India- need for conservation to sustain livelihoods

Kodagu district in South India is the largest coffee producing region in India contributing to 35% of the production under shade grown system. These diverse coffee plantations which cover 30% of the landscape in the region not only provide valuable economic gains to the community but also provide vital ecosystem services to the Southern India since the most important river of South India Cauvery originates here and coffee plantations cover a large area in the watershed. With the opening of the coffee markets and related intensification of coffee production the highly diverse coffee based agro forestry systems are losing the tree cover and tree diversity and could transform to system with few native trees and exotic fast growing trees like Silver Oak (Grevillea robusta). To address some of the issues related to loss of diversity and to promote sustainable coffee cultivation project CAFNET (Coffee Agroforestry Network) was launched in 2007 in 7 countries. In this project funded by European Union and coordinated by CIRAD France efforts are underway to strengthen ecological reasoning and to improve the business skills of farmers to negotiate access to payments for environmental services. Kodagu district is the only CAFNET site in India and multidisciplinary team of researchers are undertaking studies in 38 villages in the Cauvery Watershed region. Ecological and Socio-economic studies are being undertaken for the first time in the region to document and value the ecosystem services being offered by coffee based agroforestry systems. Efforts are underway to educate farmers and to form groups to add value to coffee through eco certification. This multi disciplinary study will help in providing much needed information on role of coffee plantations in providing key ecosystem services and to formulate guidelines for sustainable coffee cultivation and help the farmers through value addition and better access to markets. (Résumé d'auteur

Land cover changes along tropical highland agroforestry systems: call for an improved climate adaptation. [P8]

Tropical highland ecosystem resources strongly depend on climate variability and associated water availability. This work aimed at better understanding the interactions between agro-forestry systems (cocoa and coffee) and livelihoods resulting in Land Use/Cover Changes (LUCCs) along the Rungwe tropical highlands in southern Tanzania. GIS- based analysis and remote sensing methods (World view II, Landsat Thematic Mapper and Enhanced Thematic Mapper+) were undertaken to detect and map changes among four main agro-ecosystems, namely food, cash crops, forest and irrigated agro-ecosystems. Image analysis validated with geo-coding surveys evidenced significant LUCCs since 1993 along with a ca. 3% area-per-decade increase in cocoa, a ca. 6% area-per-decade decrease in coffee, and a ca. 4 % area-per-decade decrease in natural forest cover. The latter was associated with a loss of natural species such as the fire and drought-resistant miombo trees, a critical issue under currently drier conditions. In addition, primary data collection, household questionnaire surveys and key informant interviews showed that market-driven factors of LUCCs were straightforward, as illustrated by the replacement of major agro-forestry systems and/or the emergence of valuable cash crops (e.g. potato) through time. LUCCs mainly impacted crops and vegetation diversity, also resulting in increased land fragmentation. In the absence of climate-smart resource management, the land cover competition between food and cash crops was stressed as a critical threat over livelihood security. Trends in cocoa, tea and new avocado agro-forestry systems developed at the expense of coffee must be further understood as a balance between climate trends, population growth, political influences and infrastructure development. (Résumé d'auteur

Shade trees improve coffee health without reducing (too much) coffee potential yield

Shade trees are increasingly recognized to benefit to biological regulation in tropical agroforestry systems (AFS). However, studies have revealed contradictory results for cryptogrammic diseases, suggesting strong interactions with local abiotic conditions and management. In AFS, the development of diseases depend on microclimate modifications caused by shade trees. Here, we aimed at evaluating the impacts of shade trees on disease infestation within coffee AFS in Central Kenya (Murang'a). We mapped and assessed the horizontal and vertical structure of 15 AFS plots with contrasting shade tree cover and spatial organization. We monitored the incidence and severity of Coffee Berry Disease (CBD) and Coffee Leaf Rust (CLR) on 50 coffee plants with contrasting shading conditions within each plot during the harvest in 2010. Our results showed that coffee under trees, especially under dense-canopy trees (e.g. Macadamia, Mango), have similar yield potential (around 2.35 kg of cherries/ coffee plant, estimated over 5 fruiting branches) but significantly lower CBD (– 53 %) and CLR (– 13 %) symptoms. At the plot level, intermediate and homogeneous canopy tree cover enabled lower disease infestation. In addition, we showed that architectural traits of trees (e.g. growth habit, total height, crown size, foliar density) can modulate the impact of shade trees on disease regulation. Our results open perspectives for designing complex canopy structure towards healthier tropical AFS

Smallholders coffee and cocoa agroforestry systems; examples of climate-smart agriculture

Agroforestry is an agricultural practice that integrates trees on cropping systems, farms and landscapes to diversify and sustain production. Agroforestry is one key management option for climate-smart agriculture as it combines sustainable production, adaptation and mitigation of climate change, as well as food and income security through tree-crop diversification. Trees in cocoa and coffee systems have been documented to improve crop production, provide timber, fruits and other products and ecosystem services, thereby enhancing food, nutrition and income security of smallholders that produce over 80% of world cocoa and coffee. There is increasing evidence that trees, through microclimatic amelioration, enhance the resilience of cocoa and coffee systems to climate change which is threatening the livelihood of rural communities globally. Nevertheless, intensification of the production of both coffee and cacao is currently promoted mainly via improved germplasm and use of agrochemicals in monoculture, and hence removal of shade trees which decreases smallholders' ability to cope with price volatility of coffee and cacao, pests and diseases outbreaks and climate change. Agroforestry systems are well suited for risk-averse smallholders. To promote successfully an intensification of cocoa and coffee systems including agroforestry practices, two scientific approaches are currently combined: 1) participatory research taking into account local knowledge of rural communities on tree species compatibility with the main crop and suitability to match ecological niches, livelihood requirements of farmers while providing a range of ecosystem services; and 2) development of tools and models that evaluate the trade-offs or synergies in terms of resource capture and competition / facilitation between trees and the main crop in order to optimize tree species arrangement and shade management according to local conditions e.g. soil fertility, microclimate, elevation or solar radiation. (Texte intégral

Local tree knowledge can fast-track agroforestry recommendations for coffee smallholders along a climate gradient in Mount Elgon, Uganda

Arabica coffee (Coffea arabica) is economically important for many smallholder farmers in the Mount Elgon region of East Uganda, but its production is increasingly threatened by climate change. However, ecosystem services (ES) provided by companion trees in coffee agroforestry systems (AFS) can help farmers adapt to climate change. The objectives of this research were to develop agroforestry species recommendations and tailor these to the farmers' needs and local context, taking into consideration gender. Local knowledge of agroforestry species and ES preferences was collected through farmer interviews and rankings. Using the Bradley-Terry approach, analysis was done along an altitudinal gradient in order to study different climate change scenarios for coffee suitability. Farmers had different needs in terms of ES and tree species at different altitudes, e.g. at low altitude they need a relatively larger set of ES to sustain their coffee production and livelihood. Local knowledge is found to be gender blind as no differences were observed in the rankings of species and ES by men and women. Ranking species by ES and ranking ES by preference is a useful method to help scientists and extension agents to use local knowledge for the development of recommendations on companion trees in AFS for smallholder farmers. (Résumé d'auteur