Effects of controlled livestock grazing and annual prescribed fire on epigeal termite mounds in a savannah woodland in Burkina Faso

Abstract

The diversity and abundance of epigeal termite mounds were investigated in response to controlled livestock grazing and annual prescribed fire in a Sudanian savannah-woodland in Tiogo State Forest. Sampling of termite mounds was carried out in 44 subplots of 0.25 ha in a split-plot experimental design during the rainy season in 2002. There were two main plots of which one was fenced to exclude livestock grazing and the second exposed to grazing. Each of the main plots included 4 subplots with annual prescribed fire since 1992 and 4 subplots without fire. Data were collected on the number and characteristics of termite mounds. A mean density of 698 mounds ha À1 was recorded. Mounds built by Trinervitermes spp. were the most abundant followed by Cubitermes spp., Macrotermes subhyalinus and M. bellicosus. The large mound-builders Macrotermes spp. dominated the community in terms of basal area (96 % of the total) and above-ground volume (99 %). The diversity of mound types was not affected by livestock grazing and annual early prescribed fire (P > 0.05). There was no statistical effect of livestock grazing on mound density, whereas a strong depressive effect of annual fire was observed for Trinervitermes spp. mound density (P = 0.012). In this ecosystem, annual prescribed fire appeared to be the major determinant for termite mound abundance.

Termites and fire: Current understanding and future research directions for improved savanna conservation

“…'s (1976) and Benzie's (1986) studies were not replicated. Results were complementary for the two studies carried out in west Africa (Benzie 1986; Traoré & Lepage 2008); in both these studies Trinervitermes mound densities decreased significantly under fire treatment, and Macrotermes and Cubitermes mounds remained unaffected by fire. However, in the study by Trapnell et al .…”

“…(1976), Benzie (1986), Ferrar (1982), Desouza et al . (2003), Dawes‐Gromadzki (2007) and Traoré and Lepage (2008). These constitute four from Africa, and one each from South America and Australia.…”

“…Of the six studies conducted in savanna ecosystems, three dealt with fire regimes (Trapnell et al . 1976; Benzie 1986; Traoré & Lepage 2008) and three with single‐fire events (Ferrar 1982; Desouza et al . 2003; Dawes‐Gromadzki 2007).…”

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

“…The adjacent savanna was considered to be out of termitaria influences and where no termite activity was observed, but still was under the same site conditions such as soil depth and vegetation cover. We only considered the large termitaria occupied by the fungus-growing termite, Macrotermes subhyalinus (Rambur) because of its high density of 7 mounds ha −1 on average in the study quadrats (Traoré and Lepage, 2008), its large influence on soil nutrient turnover, and on woody plants in this ecosystem. The M. subhyalinus termitaria represented 92% of the whole basal area occupied by all termitaria in the 16 quadrats.…”

“…An understanding of such interaction is crucial to shape the best management regimes for Sudanian woodland, where termite mounds are prevalent (Traoré and Lepage, 2008) and exclusion of grazing, application of annual early fire and selective tree cutting of 50% of the merchantable standing volume on a 20-year rotation period have been implemented as management regimes (Bellefontaine et al, 2000). This study is part of a larger experiment established at Tiogo forest in 1992 to provide scientific evidence on the long-term effects of herbivory, prescribed annual fire and selective tree cutting on the ecology and productivity of the Sudanian woodland in Burkina Faso, so as to improve the current management regimes developed without empirical evidence (Savadogo et al, 2008;Sawadogo et al, 2005;Zida et al, 2007Zida et al, , 2009.…”