Nigeria Vegetation – SS1 Geography Lesson Note (Second Term)

Nigeria has three major vegetation zones: forest, savanna and montane. Forest vegetation is mainly trees, savanna vegetation is mainly grasses, and montane vegetation grows in highland areas such as Jos and Adamawa. Soil is the thin uppermost layer of the earth’s crust on which plants grow, and Nigerian soils fall into four zones: laterite, sandy, forest and alluvial.

Behavioural objectives

By the end of the lesson, students should be able to:

• name the three major vegetation zones of Nigeria and their subdivisions;
• describe forest, savanna and montane vegetation;
• define soil;
• name the four major soil zones of Nigeria and the places where each is found;
• state the vegetation and features linked with each soil zone.

What are the vegetation zones of Nigeria?

The vegetation of Nigeria can be grouped into three major zones.

1. Forest zone

This zone contains mainly trees. It is subdivided into:

• Mangrove swamp forest: salt and freshwater swamp
• Rainforest

2. Savanna zone

This zone is made up of mainly grasses. It is further subdivided into three:

• Guinea savanna
• Sudan savanna
• Sahel savanna

3. Montane vegetation

This is mainly found in highland areas such as Jos and Adamawa.

What are the soils in Nigeria?

Soil is defined as the thin surface of the uppermost layer of the earth’s crust on which plants grow.

Soils in Nigeria can be grouped into four major zones:

1. Zone of laterite soil
2. Zone of sandy soil
3. Zone of forest soil
4. Zone of alluvial soil

1. Zone of laterite soil

These soils are found in the interior zone of Nigeria in places such as Jos, Makurdi, Minna, Enugu and Abuja. They are associated with the Guinea savanna and are heavily leached because of rainfall. They are usually reddish because of the presence of iron.

2. Zone of sandy soil

These soils are found in the extreme northern part of Nigeria, in places like Sokoto, Katsina, Kano, Damaturu and Maiduguri. They are associated with the Sudan and Sahel savanna. They are formed because of dryness and the deposition of sand by wind.

3. Zone of forest soil

This soil is found in the southern belt and southwestern part of Nigeria, in places like Ibadan, Akure, Benin City, Ogun, Anambra and Imo. It is associated with forest vegetation and is rich in humus because of fallen and decayed leaves.

4. Zone of alluvial soil

This soil is found around Ilorin, Lokoja and the Niger Delta areas of Warri, Port-Harcourt and Calabar. It is associated with fine alluvial soil deposits at the lower course of a river.

Evaluation

1. Name the three major vegetation zones of Nigeria.
2. State the two subdivisions of the forest zone.
3. Name the three subdivisions of the savanna zone.
4. Why is laterite soil usually reddish?
5. Which soil zone is associated with Sudan and Sahel savanna?

Assignment

1. The best soil for planting is ____ soil. (a) sandy (b) clayey (c) loamy
2. Sandy soil is more dominant in which of the following areas? (a) Warri (b) Lagos (c) Kano
3. Laterite soil is more dominant in which of the following areas? (a) Makurdi (b) Lagos (c) Kano
4. Savanna vegetation is characterised by (a) trees (b) grasses (c) raffia palms
5. Soil porosity is highest in ____ soil. (a) sandy (b) loamy (c) clayey
6. Define soil erosion.
7. Mention three areas of wind erosion in Nigeria.