Simulation of some strategies to reduce the effect of climatic variability on farming systems. The case of the Pyrenees mountains

Abstract

Inter-annual climatic variations pose serious problems for animal breeding farms and it is important to try to reduce the effects of these variations. An investigation of how this can be done is presented here with particular reference to the Pyrenees mountains. In this case the overwintering period is particularly difficult, but the situation during this period depends on the climate throughout the year. In a previous paper, a model of the constitution and utilisation of hay-stocks was described. The model calculated an index of winter severity. In this paper various strategies aimed at reducing the variance in this index are tested. First, strategies involving changes in farm structure (harvest process, etc.) or different fixed management strategies (e.g. different lambing periods) are considered. Then, strategies involving modifications of management (fertilisation, etc.) in response to current conditions are considered. The simulation results indicate that strategies of this latter type are the more effective in reducing the variability in the index of winter severity.