Decision Modelling for the Integration of Woody Plants in Smallholder Farms in the Central Highlands of Ethiopia

Abstract

Farmers’ perceptions of the utility and the constraints of locally available woody species are assumed to influence the decision-making and the behaviour of tree and shrub integration into current land-use types. Accordingly, the objectives of this study are (1) to analyse farmers’ decisions in making use of woody plants under perceived constraints and (2) to analyse influencing factors that determine the deliberate tree and shrub growing behaviour.
The methodology bases on the approaches of the ’Farming Systems’ and the ’Behavioural Decision-Making’. Influence diagrams are constructed incorporating the perceived utility and decision determinants of deliberately grown woody plants. Modelling of the tree adoption behaviour of farmers employs the ’Discriminant Analytical Approach’ taking into account the identified external and internal influencing factors.
Results from the decision modelling reveal that woody plants are grown on-farm in view of the perceived utility of the species, predominantly fuelwood and timber-based produce, followed by cash-generation. Service functions pertaining to the protection of land gain secondary importance to the tree produce. Major decision determinants comprise resource-based factors, e.g. the shortage of land and seedlings or competition with agricultural crops, over stochastic-environmental factors. Results of the ’Discriminant Analysis’ confirm that the adoption of trees is characterised by the available resource base, the access to infrastructure and support services as well as by personal characteristics of the farmers.