The role of high termitaria in the composition and structure of the termite assemblage in Miombo woodlands of southern Burundi

Miombo woodlands cover extensive areas in southern and southeastern Africa, but are under high anthropogenic pressure. A conspicuous feature of this ecosystem is the presence of high termitaria (>2m high) built by fungus-growing termites (Macrotermitinae). Despite the fundamental role of termites in African ecosystems, miombo termite communities remain poorly known. We suspected high termitaria to play a structuring role for the whole termite assemblage of miombo woodlands in southern Burundi. In a formerly cleared area, in regeneration since 2009, we expected the termite assemblage to be highly impoverished. The newly growing termitaria of fungus growers might provide suitable bases for recolonisation by soil-feeding species. We recorded 25 species from more than 1000 termite samples. Fungus growers were abundant everywhere. In preserved miombo, high termitaria were home to secondary soil-feeding termite species, seldom encountered in the matrix between mounds. Bushes growing on termitaria also sustained wood-feeding species. The most remarkable feature of the assemblage was the high frequency and diversity of soil-feeding soldierless Apicotermitinae, especially in the matrix. Besides scarce Coptotermes wood feeders, Macrotermitinae were the sole inhabitants of the regenerating area. Our results emphasize the importance of high termitaria for particular soil-feeding species and wood feeders associated with the vegetation growing on termitaria. They raise the question of the ecological factors allowing the coexistence of a rich assemblage of soldierless Apicotermitinae species in the nutrient-poor matrix between mounds. The observations from regenerating miombo confirm the vulnerability of soil-feeding termites to habitat degradation and provide baseline data for future studies of ecosystem restoration.