The Effects of Prescribed Dry Season Burning on Woody Species Composition, Mole National Park, Ghana

Abstract

Fire use in protected savannas of Africa is a common practice. Fires in these savannas create many environmental benefits, such as reducing grass, brush and trees that can fuel large and severe wildfires and improving wildlife habitat. However, wrong timing of fire can threaten plants, animals and habitats. This study investigated the effects of time of burning on woody plant composition, diversity and density in the Mole National Park, Ghana. A total of twelve 300 m2 plots were systematically sampled in a 200 m × 200 m treatment plot established by Park Management each for early burn, late burn and no-burn plots. Twenty-seven different woody species belonging to fourteen families were recorded in all the treatments. Most of the species identified belonged to the families Fabaceae and Combretaceae. Vitellaria paradoxa (Shea), Terminalia avicennioides, Combretum adenogonium and Combretum molle were the most common and abundant in all treatments. A TWINSPAN on sites and species revealed four species groups based on affinity to burning time. A follow-up DCA showed a strong association between burning time and species composition, with the first two axes explaining 65% of variation. The late burn and no-burn treatments recorded the lowest diversity amongst the three treatments. Stem density was highest in no-burn treatment which had lowest species richness and diversity compared to early and late burn treatments. Early burn treatment had the highest diversity and the lowest density of woody species. The study revealed that the different times of prescribed burning influenced vegetation differently. Prescribed early dry season burning could contribute to the management of indigenous woody species in protected fire-prone savannas, because it can promote the diversity of species, as found in the Mole National Park in the Guinea savanna of Ghana.