Fig. 5. Changes in the human population and the area available per household in the Matibi II Communal Land in South Eastern Zimbabwe. With minimal external inputs, a household requires 20 ha of arable land, i.e., 4 ha with a minimum 5-yr rotation, and about 400 ha of grazing land to support a herd of 25 head of cattle and 35 goats. The threshold of 400 ha per household was reached during the 1940s. Filled bars indicate the number of people in the area (left-hand y-axis); empty bars indicate available area for farming (right-hand y-axis). Figure after Cumming (2003).