Framework for a savanna burning emissions abatement methodology applicable to fire-prone miombo woodlands in southern Africa

Background and aims

To assess development of a robust emissions accounting framework for expansive miombo woodland savannas covering ~2 million km² of southern Africa that typically are burnt under relatively severe late dry season (LDS) conditions.

Methods

A detailed site-based study of fuel accumulation, combustion and greenhouse gas (GHG) emission factor parameters under early dry season (EDS) and LDS conditions along a central rainfall-productivity and associated miombo vegetation structural and floristics gradient, from lower rainfallsites in northern Botswana to higher rainfall sites in northern Zambia.

Key results

Assembled field data inform core components of the proposed emissions reduction framework: fuel and combustion conditions sampled across the vegetation/productivity gradient can be represented by three defined Vegetation Fuel Types (VFTs); fuel accumulation, combustion and emissions parameters are presented for these. Applying this framework for an illustrative case, GHG emissions (t CO₂-e) from EDS fires were one-third to half those of LDS fires per unit area in eligible miombo VFTs.

Conclusions

Our accounting framework supports undertaking EDS fire management to significantly reduce emissions and, realistically, burnt extent at landscape scales. We consider application of presented data to development of formal emissions abatement accounting methods, linkages with potential complementary woody biomass and soil organic carbon sequestration approaches, and necessary caveats concerning implementation issues.