(a) On a sketch map of Nigeria, locate and name three vegetation zones, choosing at least one from each of the two broad belts (b) Relate the characteristic...

Answer Details

(a) Sketch map of Nigeria showing three vegetation zones (at least one from each broad belt)

Nigeria's natural vegetation is grouped into two broad belts: the forest belt in the rain-soaked south and the savanna belt in the drier north. The belts run roughly east–west, becoming drier as one moves from the coast towards the far north. Choosing across both belts, the three zones located and named on the map below are:

• Mangrove & fresh-water swamp forest — forest belt, along the southern coast and the Niger Delta.
• Guinea savanna — savanna belt, the wide Middle Belt across the centre.
• Sudan savanna — savanna belt, the far north.

(b) Relating the vegetation to the climate of one zone (Sudan savanna)

The Sudan savanna experiences a single short rainy season of only about 500–750 mm (50–75 cm) of rain, followed by a long, hot dry season dominated by the dry, dust-laden Harmattan wind. Temperatures are high all year. Because rainfall is low and the dry season is long, the vegetation shows the following features, each a direct response to the climate:

• Short grasses that dry up and turn brown in the long dry season, because the rains are too brief to support tall growth.
• Scattered, drought-resistant trees such as the baobab, acacia and silk cotton, widely spaced so that each can draw enough moisture from a large area.
• Small, thorny or reduced leaves and thick, fire-resistant bark, which cut down water loss through transpiration during the hot, dry months.
• Long tap roots that reach deep for underground water.

Thus the sparse, thorny, drought-adapted vegetation of the Sudan savanna is a direct reflection of its low, strongly seasonal rainfall and high temperatures.

(c) Two major agricultural produce from any two of the zones