Long-term effects of Macrotermes termites, herbivores and annual early fire on woody undergrowth community in Sudanian woodland, Burkina Faso

• We assessed termitaria, herbivores and fire effects on woody species regeneration.
• We compared undergrowth and tree communities on termitaria and in adjacent savannas.
• Termitaria increased species diversity and density under fire and grazing events.
• Undergrowth and tree communities on termitaria were significantly similar.
• We highlighted termitaria as refuge and facilitator for woody species regeneration.

Termites, herbivores and fire are recognized as major guilds that structure woody plant communities in African savanna and woodland ecosystems. An understanding of their interaction is crucial to design appropriate management regimes. The aim of this study was to evaluate the long–term impacts of herbivore, fire and termite activities on regeneration of trees. Permanent experimental quadrats were established in 1992 in the Sudanian woodland of Burkina Faso subjected to grazing by livestock and annual early fire and the control. Within the treatment quadrats, an inventory of the woody undergrowth community was conducted on termitaria occupied by Macrotermessubhyalinus, extended termitosphere (within 5 m radius from the mound base) and adjacent area (beyond 5 m from the mound base). Hierarchical analysis was performed to determine significant differences in species richness, abundance and diversity indices among vegetation patches within fire and herbivory treatments. Grazed quadrats had significantly (P < 0.001) more species and stem density of woody undergrowth than non-grazed quadrats but maintained similar level of species richness and stem density of woody undergrowth on termitaria. There were not significant differences (P > 0.05) in species richness and stem density between burnt and unburnt quadrats. Termitaria supported a highly diverse woody undergrowth with higher stem density than either the extended termitosphere or rest of quadrats. The density of woody undergrowth was significantly related with mature trees of selected species on termitaria (R2 = 0.593; P < 0.001) than that on the extended termitosphere (R2 = 0.333; P < 0.001) and adjacent area (R2 = 0.197; P < 0.001). It can be concluded that termites facilitate the regeneration of woody species while grazing and annual early fire play a minor role in the regeneration of woody species. The current policy that prohibits grazing should be revised to accommodate the interests of livestock herders.