The bacteria convert nitrogen from the air into nitrates which the tree can use to grow and reproduce, whilst the soil is also enriched. The leaves of trees are eaten by many insects as well as monkeys, elephants, giraffes, kudus and bushbucks. Even fallen dead leaves are eaten - they are a favourite food of the blue duiker. Flowers are eaten by monkeys, and nectar by birds, insects and bats. Many fruits are eaten by animals, some of which aid seed dispersal.
Trees provide nest sites for birds.
Woodpeckers, barbets and hornbills nest in holes in trees. Very large, old trees frequently develop a hollow centre, a favourite breeding and roosting place for bats. When dead, their rotting wood is a source of food for insects and their predators. A widely-used building material, its strength and lightness often gives it the advantage over concrete and steel. Modern buildings still require timber in roof construction.