Dominant Species’ Resprout Biomass Dynamics After Cutting in the Sudanian Savanna-Woodlands of West Africa: Long Term Effects of Annual Early Fire and Grazing

BACKGROUND

This study examines the potential for forest regeneration after harvest in Burkina Faso, West Africa. The study area is a tropical dry forest of tree-shrub dominated by trees of Combretaceae and Mimosaceae (Fabeaceae). The area is part of the Sudanian savanna ecoregion, stretching across Africa , and receives approximately 700-1200 mm of rain, interspersed by a 6-7 month dry season. Firewood is the major source of home energy. It is estimated that 25-50% of the forest area naturally burns each year, and all areas burn every 2-3 years. Cattle browsing is also common in the region, especially on the grass that sprouts after burns.

RESEARCH GOALS & METHODS

The authors use a factorial experiment to examine the long-term effects of annual early burning and grazing on dominant species’ resprout biomass dynamics after selective cutting in the Sudanian savanna-woodlands of Burkina Faso, West Africa. Researchers record the shoot survival of trees in grazed and non-grazed areas, with fire and without. Species monitored include Crossopteryx febrifuga, Detarium microcarpum, Acacia macrostachya, Entada africana, Combretum ghazalense and Combretum glutinosum. 

CONCLUSIONS & TAKEAWAYS

The study finds that burning regimes do not affect mortality of A. macrostachya and C. glutinosum, and  that burning promotes survival of E. africana and C. febrifuga. Grazing increases the mortality of D. microcarpum and E. africana, and burning increases the basal area in C. glutinosum but reduces that of A. macrostachya, C. febrifuga, and D. microcarpum. The authors conclude that livestock grazing could be integrated into forest management practice, while greater attention should be paid to burning practices.