Impact of bark and foliage harvesting on fruit production of the multipurpose tree Afzelia africana in Burkina Faso (West Africa)
Afzelia africana is listed as an endangered species on the national red list of Burkina Faso
Intensive exploitation of this species for timber, used by the international market, is a significant threat. It is also becoming threatened where there is high pressure for fodder, such as in Mali, Burkina Faso, Benin, Nigeria and Cameroon (Gérard and Louppe 2011). Cutting the branches for livestock fodder and debarking for medicinal purposes is uncontrolled in eastern Burkina Faso and this harvesting has negatively affected the population structure and fruit production of this species (Nacoulma et al. 2011, 2017).
In the Northern and West Nile regions of Uganda, this species has declined dramatically in recent years due to harvesting for charcoal and carvings for the tourist market (Kirunda et al. 2016). In the last two years, Uganda has experienced rampant illegal harvest of the species in protected areas and private land mainly for timber export to Asia. This prompted a government ban on the harvest and trade in 2017, though this did not stop the export trade (I. Katwesige pers. comm. 2019). In South Sudan, this species is heavily used and considered threatened (M. Kordofani pers. comm. 2020). General habitat loss such as forest clearance for agriculture is also a threat in parts of this species range (Onana and Cheek 2011).
bark and foliage harvesting
The bark is harvested and used as an important medicine to treat various diseases, including diar- rhoea, coughs, gastrointestinal disorders, general pain in humans and in veterinary medicine (Arbonnier 2002; Orwa et al. 2009). Afzelia africana is also used for religious purposes (a fetish tree) in many regions and the bark is removed both for medicinal purposes and for sacrifices throughout the year; Being among the most used fodder tree species, Afzelia africana foliage is heavily harvested to feed livestock;
The study was conducted in W National Park (WNP) complex and surrounding areas in Burkina Faso, located in the Sudanian zone between lat. 11° 300 N to 12°220 Nandlong.1°460 Eto2°230 E.
High harvesting intensity is an unsustainable practice that should be completely prohibited in order to ensure long-term persistence of Afzelia africana. Low harvesting intensity should be allowed, but only on large reproductive individuals.
Nacoulma, B.M.I., Lykke, A.M., Traoré, S. et al. Impact of bark and foliage harvesting on fruit production of the multipurpose tree Afzelia africana in Burkina Faso (West Africa). Agroforest Syst 91, 565–576 (2017). https://doi.org/10.1007/s10457-016-9960-9
Fruit and seed quantity and quality decreased with increasing harvesting intensity. However, no significant differ- ence was detected between trees without and trees under low harvesting. Trees of all size classes under very severe harvesting intensity had no fruits. Under low harvesting impact, large trees had twice as many fruits as the control, whereas fruits were reduced by half to 95 % for the small trees.
Our study highlights that bark and foliage harvest- ing occurring in the Sudanian savanna is detrimental to the performance of Afzelia africana fruit production. Harvesting significantly decreased the quantity and quality of fruits and seeds, which could compromise the chances of natural regeneration of this multiuse tree species in the long-term.
TheWNP complex includes two protected hunting zones (Tapoa-Djerma and Kombongou) in addition to the national park