Vegetation

In Nigeria there are two broad types of vegetation. Forest and savanna. The difference in vegetation from place to place is caused by climate, soil, topography and man.

• Forest:  

The original forest cover the southern parts of the country where the mean annual rainfall is about 1150mm. however, the original forestland has been reduced by human activities from tropical rainforest to secondary forest and derived savanna.

The vegetation of the forest region is sub-divided into three sub-types include: mangrove swamp forest, Deltaic swamp forest and Rainforest.

i. The mangrove swamp forest, varieties of the same species especially red mangrove between 10-15m tall are found along the lagoon and in the drier land away from the river coconut trees and reeds tend to replace mangrove.

ii. Deltaic swamp forest is a fresh water swamp forests which occur intensively in the Niger Delta and in the flood plains of large rivers common trees there are: Raffia palm, abura, mahogany, sass woods.

iii. Rainforest is found in the West-Ibadan, Niger, Benin and a few forest reserves of it in Ondo also in the Cross River basin along the boarder with Cameroun. High relative humidity, look at it now the high rain forest we know before it as restricted to a few forest reserves just as mention above. The high forest consists of evergreen plants and trees that grow to various heights.
 

• Savanna

The savanna zone have a high rural population density, they practice shifting cultivation. The original forest vegetation is burn annually to derived savanna; meanwhile looking at some areas you can found only a few forest trees remain as evident to show the original forest. The savanna is characterized by grass land with scattered trees.

The savanna vegetation may be sub-divided into four types. They are as follows:

• The woodland savanna which trees and shrubs form a close canopy. 
• The scattered savanna where the trees and shrubs spread far apart over a wide area. 
• Dead land savanna where trees and shrubs absent. Shrubs savanna where trees are absent.

In Nigeria the savanna zone is split into two:

1. Guinea savanna and 
2. Sudan savanna.

The Guinea savanna is the largest vegetation zone in Nigeria and where you find the great population of the middle belt. Guinea savanna extends from the South around Enugu to the North toward zaira. The rainfall in this zone is between 100 – 150cm and 6 months wet season in the North and 8 months in the South. The trees are devasted by human activities and grow long tap-roots to survive the hard condition, also the grasses have durable roots to survive dry season fire by men. Elephant grass is the common grass there with a height of about 3.6m.

Sudan savannas, in this zone intense cultivation with over-grazing and bush burning carryout have depleted the grassland that covers large areas.

The grasses are short between 1.5m and 2m high and stunted trees like silk cotton, baobab and acacia, in the dry season the water they store in the trunk, that it what they used to over come the hard condition.

The Sudan savanna extends from Sokoto through Kano to some parts of Borno and Adamawa. Experience’s seasonal rainfall (about 65 and 100cm) and lower relative humidity below 40%. The dry season is longer about 6 and 8 months.

This zone has the greatest density of population in the Northern parts, due to the growing of cotton, millet, groundnut and maize. Has the highest concentration of cattle. It has a clay soil but shrinks and cracks in dry season. 

 

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