Assisted Natural Regeneration in slash-and-burn agriculture: Results in the Democratic Republic of the Congo

Abstract

Human impacts on natural tropical forests in Central Africa are to a large extent linked to shifting cultivation and fuelwood ex- traction in peri-urban areas. This is espe- cially true around the city of Kinshasa in the Democratic Republic of the Congo (DRC), which is why research was con- ducted in 2010 by the Makala Project in the city’s fuelwood supply basin. The aims were to adapt and test Assisted Natural Regeneration (ANR), improve slash-and- burn crop systems and contribute to the enrichment of forest fallows. Prior to slash- ing and burning, useful trees were se- lected for protection. Then, during crop- ping, the germination and multiplication of stump shoots and root suckers from ex- isting local forest species were promoted by selective weeding, thinning, and prun- ing. Monitoring of the test areas found low survival rates for old trees conserved be- fore the land was slashed and burned, due to the difficulty of controlling the fires. This means that the technique can only be used for the edges of plots, by gradu- ally enriching hedgerows. In contrast, stumps shoots and root suckers from nat- ural forest species protected by ANR dur- ing agricultural weeding grew rapidly in- side the plots, thus rapidly establishing woody fallows without the need for costly inputs or heavy labour. In 2014, three and a half years after slashing and burning, biodiversity and biomass in these fallows is greater than in non-ANR fallows. Better charcoal and crop productivity and a slower rate of forest transition into savan- nah are expected. However, social accept- ance, a critical factor in the large-scale dissemination of this innovation, must be investigated in the light of potential de- velopments in traditional and modern land tenure rights.