Miombo is one of the major dry forest-savannah biomes of the world. It covers much of southern Africa, stretching from mid-Tanzania across to Angola, and down to the northern edge of South Africa, and constitutes the single largest vegetation type in East Africa. The web pages of the International Geosphere-Biosphere Programme’s Miombo Network have an expanded technical definition. In miombo competition for water during the dry season causes the trees to be quite widely spaced such that their canopies do not form a complete cover. Grasses take up water in the upper horizons of the soil. Any water that infiltrates deeper is used by trees, which are thinned out by competition as they grow.
Miombo is characterised by trees in the sub-family Caesalpinoideae, especially species in the genera Brachystegia and Julbernardia. Typically miombo trees are semi-deciduous meaning that they lose some or all of their leaves in the dry season depending on its severity. The shrub layer is variable in density, percentage cover and species composition, and is commonly dominated by Diplorhynchus and Combretum species. Miombo's structure and composition is largely maintained by periodic dry season fires, which can be a frequent as twice a year in populated areas.
Miombo has been described as "arguably the most important wildlife preserve in the world ... in respect of its animal and plant life alike." Buffalo, warthog, elephant, hunting dog and lion are among the species of game found there. However miombo is a heavily human-influenced landscape and is everywhere under threat from increasing fragmentation. The above-mentioned populations of large mammals require large contiguous ranges, and are likely to suffer drastic declines in numbers if the present rate of clearing and burning continues apace.