THE BURNING OF FUELWOOD IN SOUTH-AFRICA - WHEN IS IT SUSTAINABLE

Fuelwood harvesting is considered sustainable when consumption is equa l to or less than production. An empirical model was developed to esti mate potential fuelwood production from savannas. The model is based o n the observation that in semiarid savannas, biomass production is lin early dependent on rainfall. Woody basal area is linked to mean annual precipitation, and aboveground woody biomass is proportional to basal area. Production averages 4% of standing woody biomass and is correct ed to exclude stems that are too small for harvesting. The model assum es that the entire area consists of seminatural savanna Corrections fo r the land lost as a result of land transformation and degradation wou ld have to be included. Data on land loss can most effectively be obta ined from satellite imagery, with appropriate ground calibration. The model is based on limited data sets but in most instances has been val idated against independently collected data. The model yields a reason able prediction at a national and regional level, but estimates for li mited areas or specific points on the ground may differ substantially from the predicted values. Model results indicate a potential for sust ainable fuelwood production at the national level, but specific region s are using fuelwood at nonsustainable levels.