Kumasi is the second largest city in Ghana, after the capital Accra, and functions as the administrative, commercial, industrial, and cultural center of the Ashanti region. Owing to considerable rural-urban migration driven by the growth of industries and commercial activities in and around the city, the population of Kumasi has increased sharply over the past four decades. The census of 1970 reported 346,000 inhabitants, surpassing 1 million by 2000 and over 2 million in 2013 (GSS, 2013).
The comparison of a Corona satellite image from 1966 with a Landsat image from 2014 shows the expansion of built-up area from 60 sq km in 1966 to over 400 sq km in 2014, in parallel with the population growth in the Kumasi metropolis. The influence of the city on land cover change reaches far beyond the immediate peri-urban area. While agriculture, mostly in the form of shifting cultivation, was certainly present in greater Kumasi in 1966, by 2014 the forest and woody savanna has become considerably more fragmented within a radius of at least 50 km of the urban fringe, creating a fine mosaic of cultivated land and degraded forest.
The Bobiri Forest Reserve, 20 km east of Kumasi, illustrates the contrast between this mosaic and a continuous forest canopy. In 1966, the forest reserve completely blended in with its surroundings. Although it contains nearly 50 sq km of forest, the reserve is far from pristine. It has already been actively exploited for timber, and its more accessible parts are known to be moderately to severely degraded. By 2014, fairly large clearings for cultivation and palm wine tapper camps are visible inside the reserve. Locals collect firewood, and the felling of small trees is not uncommon. On the positive side, the reserve also includes significant sections of intact high canopy forest and hosts a forest arboretum with about 100 indigenous tree species. The reserve also has a butterfly sanctuary with 340 butterfly species, which is managed according to an ecotourism plan for the benefit of local communities.
Between 1966 and 2014 in the Bandai Hills, a contiguous area of degraded forest of 130 sq km has been cleared for cultivation to the northeast of the town of Agogo, leaving a visible footprint in the 2014 Landsat image. However, deforestation is not a new phenomenon in Ghana. Encroachment of agriculture into forest has accelerated dramatically in recent years, but historical research has shown that much of the forest inside and outside of reserves is not primary, but regenerated secondary forest on previously cultivated and depopulated lands.