Nigeria’s forests can be divided into two principal categories: woodlands and forests of the savanna regions (fourfifths of the country’s forest area) that are sources of fuel and poles, and rainforests of the southern humid zone that supply almost all domestic timber and lumber, with fuelwood as a byproduct. Nigeria’s forests have gradually shrunk over the centuries, especially in the north, where uncontrolled commercial exploitation of privately owned forests began in the late nineteenth century.