A system of agricultural activities integrated into a wildfire prevention system is an economically efficient participatory approach. The concept of fuelbreaks follows the principle of creating fire barriers (or buffer zones) in which the combustible materials (fuels) are modified in such a way that the intensity and rate of spread of a wildfire will be reduced to such an extent that the fire can be suppressed by the means available. Fuelbreaks also provide easier and safer access to a closed forested area for fire fighting.
While firebreaks are constructed in such a way that all plant material is removed and the mineral soil is exposed completely, the concept of fuelbreaks provides for continuation of plant production (or vegetation cover), either by growing trees and/or agricultural crops or by maintaining strips of grazing land. The labour invested in planting and cultivating crops is simultaneously utilized for wildfire hazard reduction.
The social and ecological conditions of Jebel Marra, Sudan, were considered favourable for the use of this system (Goldammer 1991). Restrictions were determined (1) by the site condition (suitability of the sites for agricultural production) and (2) by the distance to the villages from which farmers are to be recruited.
Permanent agro-silvopastoral fuelbreaks offer the advantage of having local farmers actively engaged in fuelbreak maintenance on a permanent basis. Certain crops, such as groundnuts and legumes, are especially suitable because they have little aboveground biomass (fuel) and are harvested completely. In the case of millet, the most important agricultural crop in the area, the contract with the farmer should be written so that all the aboveground plant biomass must be removed immediately after harvest, generally around the beginning of the dry season. Usually the stems of millet are removed only at the end of the dry season. This highly combustible material, if left on site, constitutes a considerable risk that fire would be carried into the adjoining forest plantation). Farmers can be motivated to use the assigned land by providing it on a cost-free base and also by doing the initial ploughing by tractor.
Fuelbreaks that are stocked with wide-spaced trees ("shaded fuelbreaks") are designed as agroforestry or silvopastoral systems. The spacing of trees depends (1) on the demand for light and water by the trees or by the grass grown under them and (2) on the topography of the terrain. The open tree overstorey needs to be carefully thinned and pruned (removing ladder fuels) and the slash and any encroaching brush and tree vegetation must either be disposed of by prescribed fire or cleared mechanically. Shaded fuelbreaks in general are designed to produce high-quality timber (via pruning) in rotation periods that are determined by the timber market (critical diameters).
