Documenting local tree knowledge and developing a decision-support tool to improve resilience of agroforestry systems in mountainous areas of Laos and Vietnam
Over the past decades, agricultural systems have been intensified and simplified, particularly in South-Eastern Asia (SEA) relying more and more on agro-chemicals and full sun monocultures that are not long-term sustainable and have a negative environmental footprint. This has resulted in an enhanced soil degradation, particularly soil erosion in mountainous areas of this SEA region. The association of trees on farm, with perennial crops such as coffee as well as food crops and in silvo-pastoral systems, is recognized to be part of an agro-ecological approach to agricultural landscapes.
Trees in agroforestry systems help rural households to diversify their on-farm activities via fruit production, timber and fodder for dairy-livestock production and hence their revenues (fruits, timber, fuelwood, fodder, medicinal products, honey...); this reduces their exposure to agricultural price volatility. Trees contribute greatly to 1) improve soil fertility by reducing soil erosion and enhancing nutrient cycling; 2) buffer climate extremes (notably frost at higher altitude) and hence help farmers adapt to climate change; 3) provide a micro-climate often conducive to the development of antagonists to pests and diseases; 4) provide refuge for biodiversity conservation; and 5) produce fodder to improve diet of livestock. However, trees can also compete for natural resources (water, light, nutrients) and favour pests or diseases, hence providing ecosystem disservices when farmers use locally inadequate tree species and/or agroforestry management practices (Vaast et al, 2016).
Over the past years, a methodological approach has been developed and tested in cocoa landscapes of Ghana (Graefe et al, 2017) and coffee landscapes in East Africa (Gram et al, 2017) in collaboration with CIRAD, ICRAF, IITA and local partners. This approach allows to document and value local knowledge on native and exotic tree species in terms of ecosystem services and disservices that trees provide to these two economically important perennial crops. Clearly, the methodology can be adapted and transferred to any other cropping systems, including food crops and tree fodder for livestock.
This work has also resulted in the development of a decision-support tool that allows extension services to guide farmers in the selection of the tree species best adapted to the local ecological context and in accordance with the households’ needs and constraints. This tool, in prototype form, is available on line and can be used to get recommendations on tree species selection in Western Ghana, on the slope of Mount Elgon in Uganda and very recently in the Yunnan Province in China. A presentation of its main features is also available online. Details on the methodological approach are described in van der Wolf et al (2016) and rapidly illustrated below.
The objectives of this proposal are
- to document local knowledge of tree species (exotic and native, and legume or not legume) with respect to ecosystem services and disservices in two mountainous regions of Laos and Vietnam,
- to develop a decision-support tool to help extension services of agricultural services, farmers’ cooperatives and NGOs select the right tree species adapted to local ecological conditions and households’ needs and constraints,
- to increase the sustainability of cropping systems and the economic sustainability of households to agricultural price volatility through production and revenue diversification
- to facilitate adaptation of rural communities to climate change via the adoption of climate-smart practices, particularly agroforestry.
- CGIAR-ICRAF (Vietnam)
- NOMAFSI Vietnam
- CPC Laos
- DP CANSEA
Contact et Informations
Philippe Vaast, UMR Eco&Sols, Cirad Vietnam