Miombo

Miombo is a widely settled forest-savanna type ( tree savanna ) with little undergrowth in south-central Africa, where the term is also used beyond these limits. The term comes from the miombo in some dominant woody species Brachystegia boehmii and B. longifolia, which in some regional languages ​​Muombo (plural: Miombo ) are called.

Distribution area

Miombo are encountered in the countries of Zimbabwe, Zambia, Mozambique, Angola, Tanzania and Malawi. With approximately 5 million square kilometers throughout the miombo Africa forms the largest dry forest area in the world.

Characteristics

The Miombo is characterized by the three typical plant genera Brachystegia with 21 species, Isoberlinia with 3 types and Julbernardia with 2 types. They have pinnate leaves and a characteristic umbrella shape. The trees form a loose forest whose floor is only sparsely covered by grasses and shrubs. Miombo is developed mainly on nutrient-poor, acidic and geological- pedological old floors ( Ultisole, Alfi sols Oxisole, Vertisols, Entisole ). The rainfall dependence is relatively low: miombo can keep in dry savannahs at about 650 to 1000 mm annual rainfall, but also in humid savannah with up to 1500 mm of rain. However, the rain does not fall in this region throughout the year; there is a pronounced dry season during the months of May to November. It follows that the plants are occasionally exposed to extreme stress due to drought, which can be enhanced by surges of cold air with frost still on.

Human influence

It is not uncommon in the dry season fires. While some fires are caused by lightning, but the real driving force is the man. Deforestation of miombo be traced back to about 3000 years ago, so that now an equally natural stage has settled in the miombo. Today, the open miombo even need the frequent fires. They destroy again a part of the trees, which also other plants such as grasses and bushes can develop in the Miombo itself.

Increasing exploitation

The campaign " smoke signals " [web 1] has made ​​it his mission to educate about the consequences of tobacco cultivation in Africa. The Miombo dry forest is now cleared for example, in Tanzania in an excessive way to plant tobacco, but especially for drying tobacco. The furnaces used for this purpose are very inefficient heating. To dry one ton of tobacco you need an average of 150 tons of wood. Satellite images testify that by the year 1991, around 44 percent of the tree population were destroyed in the Malawian region Namwera forever from the 1970s. But the Virginia tobacco farmers, who make up only three percent of all farmers in Malawi, are responsible for 80 percent of the total clearcuts.