As the climate and ecology of Nigeria vary, so do the ecological zones of Nigeria. Nigeria has two major ecological zones and they are the Savannah and Forest ecological zones. These ecological zones are subdivided into three each known as Vegetation belt. The Forest zone is subdivided into: Mangrove or Salt water swamp, the Fresh water swamp and the High or Rain forest while the Savannah is subdivided into Guinea savannah, Sudan savannah and Sahel savannah. Guinea Savannah is the largest vegetation belt in Nigeria.
Table of Contents
Ecological zones of Nigeria
- Forest Ecological Zone
- Savannah Ecological Zone
Broadly, Nigerian vegetation can be divided into 2 broad groups the forest and the Savannah zones. These broad divisions can however be subdivided into 3 types each giving rise to 6 ecological zones.
Subdivisions of the Forest Ecological Zone
- The salt water swamp
- The fresh water swamp
- The rain or high forest
Subdivisions of the Savannah Ecological Zone
- The Guinea savannah
- The Sudan savannah
- The Sahel savannah
Each of these ecological zones have unique characteristics which collectively provides Nigeria with greater opportunity for greater agricultural production.
Subdivisions of the Savannah Ecological Zone
- The Guinea savannah
- The Sudan savannah
- The Sahel savannah
Each of these ecological zones have unique characteristics which collectively provides Nigeria with greater opportunity for greater agricultural production.
Characteristics of Salt water swamp
- Plants of the mangrove forest (salt water swamp) have aerial root system that help them to
- stand above the salt water to breath
- The trees of this environment are tall and woody (over 15 meters)
- They are broad leaved evergreen plants
- Mangrove swamp have very low animal population
- The woods are tough and good for building canoes
Characteristics of Fresh water swamp
- The plants here are tall woody plants with few undergrowth
- The waters and soils of the fresh water swamp are not salty
- The plants generally have buttress root system with few having stilt roots
- They are also evergreen broad leaved plants
- Fresh water swamp enjoy good measure of rainfall (over 200 cm per annum)
Characteristics of the high (rain water) forest
- Rainfall here ranges between 150 and 200 cm per annum
- The forest is a luxuriant evergreen forest
- Because of heavy canopy, the forest have thin undergrowth
- The forest canopy is divided into 3 stories: The upper, Middle and Lower stories
- This forest have many climbers (Epiphytes) and parasitic plant species
- The upper canopy trees usually have buttress root system to support them
Characteristics of Guinea Savannah
- The vegetation has a combination of forest and savannah characteristics mixed up
- The southern part has more of the forest characteristics while the northern part have more of the characteristics of savannah zone
- The trees are mostly deciduous trees (trees that shade their leaves during the dry season)
- The grasses here are tall and have deep roots
- The trees have thick backs to protect them against common bush fires of the savannah.
Characteristics of Sudan Savannah
- The vegetation belt is dominated by grasses and shorter trees scattered all over
- Gallery forests align water channels like rivers and creeks
- The trees generally have long tap roots to reach for deeper waters
- The trees are deciduous by nature
- Some trees have narrow leaves while others have thorns instead of leaves which help them adapt to the dry environment and reduce evapotranspiration
- Some shrubs in this vegetation dry up during dry season and sprout back with the rains
- The trees have thick scaly backs that acts as fireproof against the rampant bush fires of the Savannah
Characteristics of Sahel Vegetation
- The Sahel environment receives the least amount of rainfall (less than 65 cm per annum)
- It has the longest dry and the shortest rainy seasons
- The grasses are relatively shorter and scanty
- Xerophytic plants like baobab are scattered all over the zone
- The scanty rainfall leads to the development of shrub lands