Forage-SAFE: a model for assessing the impact of tree cover on wood pasture profitability

Whilst numerous studies have examined the environmental benefits of introducing additional trees within wood pasture systems few studies have assessed the impact on farm profitability. This paper describes a model, called Forage-SAFE, which has been developed to improve understanding of the management and economics of wood pastures. The model simulates the daily balance between food production and the livestock demand for food to estimate annual farm net margins. Parameters in Forage-SAFE such as tree cover density, carrying capacity, and type of livestock can be modified to analyse their interactions on profitability and to identify optimal managerial decisions against a range of criteria. A modelled dehesa wood pasture in South-western Spain was used as a case study to demonstrate the applicability of the model. The results for the modelled dehesa showed that for a carrying capacity of 0.44 livestock units per hectare the maximum net margin was achieved at a tree cover of around 53% with a mixture of Iberian pigs (28% of the livestock units) and ruminants (72%). The results also showed that the higher the carrying capacity the more profitable the tree cover was. This was accentuated as the proportion of Iberian pigs increased.