The geographical area called Nigeria has a total land area of 983,213 km2 with over 180 million people living in it. The country is covered by three major types of vegetation which include forests, savannahs and montane land.
In this post, we’ll find out what these vegetation types mean and we’ll further divide them into other zones.
Types of Vegetation Zones in Nigeria
Forests are areas where there is significant tree cover. The forest zone is located in the southern part of Nigeria. They are identified with the mangrove swamps located around the delta region of River Niger and Cross River.
At the northern part of this region is fresh water swamp. There is also the salt water mangrove swamp as well as the rain forest which is located north of this swamp.
Savannahs are area with insignificant tree cover with grasses and flowers found between these trees.
There are three categories within the savannah zone. These include the Guinean forest-savanna mosaic comprising plains of tall grasses and trees. Then there is the Sudan savannah which is similar to the Guinean savanna but has shorter grasses and trees
Finally, there’s the Sahel savannah which is made up of patches of grass and sand and this savannah is found in the North-East.
Montane land is the least common and is typically found in the mountains close to the Cameroon border.
Generally, the vegetation found in any area is dependent on the climate of that region.
Broadly, these vegetation belts are classified into the following:
- Fresh Water Swamp;
- Sahel Savanna;
- Short Grass Savanna;
- Guinea Savanna;
- Marginal Savanna;
- Sudan Savanna
In the past, a large part of the geographical area called Nigeria was covered with dense tropical rainforests however deforestation and burning out of crop plots led to a drastic reduction in the area of forests that now occupy about one-third of the territory.
Basically, the rainforest is made up of high-mountainous multi-tiered tropical forests which are usually found along the right bank of the lower reaches of the River Niger and in the valley of the Cross River.
The trees have a height ranging between 40-45 m. These form the first upper tier and they are known for their powerful tree-shaped roots, diverging from the base of the trunk.
There are also the second and third tiers trees which are densely strewn with epiphytes and intertwined with lianas that grow northwards towards the sun.
As a result of this dense green canopy formed by the woody crowns coupled with annual rainfall which doesn’t exceed 1600 mm, the humidity level is low and the soils are drier.
There are some trees in the rain forest which are known as the dry tropical trees. These trees shed their leaves during the dry season.
As you move further north of the rainforest, the forest become sparser leading to the savanna region.
This region is made of high grass and average rainfall per year is 1000-1400 mm. The grasses are high enough for large animals to hide beneath them.
Additionally, there are groups of trees that rise above these grasses, some of which include the drought-resistant kaya, isoberlinia and mitragina.
Some of these trees have twisted trunks which are the result of annual fire.
During the first half of the dry season the savanna looks lifeless as the trees stand bare but as we progress to the middle of the season, a smoke screen rises over the savanna and the dry grass burns, this helps to prepare the land for crops. By the time the first rain falls, the savannah comes alive with juicy shoots of young grass and green leaves appearing.
This is located north of the Guinea savanna and the annual rainfall in this region reduces by a further 500 to1000 mm with the dry period lasting 6 to 7 months
The zone is made of dense but low grass cover. The savannah has a distinctive landscape as a result of the presence of different types of acacia with an umbellate crown and thorny bushes.
The other trees in the Sudan Savanna include baobabs. Next to them, you can meet the palms of doom, the whale, the whitish acacia, which sheds the leaves in the wet season, and during the draught is covered with fresh leaves serving as food for animals.
The camels in the savannah use the young shoots of these bushes.
The Sudan Savanna provides an excellent environment for agriculture and animal farming in the Northen part of the country. It is a common site to see herds of sheep, cattle and goats grazing on the vast pastures.
This savanna is known for its desert vegetation. The annual rainfall is poor and the wet season lasts 3 to 4 months, the grasses in this region are extremely short. Some of the plants in this zone include Ngibbi, Acacia raddiana, Leptadenia, and the African myrrh.
This zone is located in high-mountain areas. The montane zone is known for its low average temperature. The Jos plateau is a typical example of the montane zone.
This zone provides a good environment for growing rich crops of different vegetables and small grain crops
This is found in the coastal location of the zone and it is influenced by the saltish sea water as a result, the soil in the Mangrove zone is extremely poor and contains salt.
However, the non-salt marshes are more stabilized and provide excellent condition for growing rice.
These vegetative zones are also known for their economic benefits. For instance, kaya, sapel, iroko, opepe, agba and obeche produce ornamental and construction timber.
Also, the leaves of the candelabra-shaped pandanus are used for weaving mats and baskets while the leaves of raffia palm are used as roofing material.
Additionally, the juice of the wine palm is used to produce wine while cash crops like cocoa, peanuts, cotton and many tropical crops are foreign exchange earners