POPULATION IN NIGERIA

POPULATION IN NIGERIA

The population is defined as the total number of people living in a geographical location at a particular time.

Population Concept

1. Over Population:-It is defined as the situation when a country has more people than its physical and human resources can accommodate. It other words, it refers to a situation where the population exceeds the available resources of the country.
2. Under Population:-This is the type of population that is less than the available resources of the country. It then means that the size of the population is so small that when combined with the available resources.
3. Optimum Population:- It is defined as the population which is neither too small nor too great, but when combined with available resources and given the level of existing technology it will secure a minimum return per head.
4. Population Density:-This is the number of persons per square km of land. It can be expressed thus Total Population/Land Area 
5. NOTE:- Total population = Population Density x Land Area while Land Area = Total Population/Population Density.

1. Example:
   Calculate the population density of Nigeria having a total population of 140,003,542 with a total land area of 923,768 sq km
   140,003,542/923,768 =151.56
   POPULATION DISTRIBUTION
   The population of Nigeria is not evenly distributed. There are areas of high, moderate, low population density.
   AREAS OF HIGH POPULATION DENSITY IN NIGERIA
   
   1. The Yoruba land of South-West which includes Lagos, Ibadan, Akure, Abeokuta.
   2. North-Central which include Kaduna, Kano, Jos, Sokoto
   3. The south-eastern part which includes Enugu, Onitsha, Owerri, Aba.
   
   
   Reasons for high Population Density.
   
   1. Favorable Climate:- The above area have adequate rainfall which ensures the production of food, especially in the west and east and is also favorable for human habitation.
   2. Fertile Soil:-Fertile soil favors the cultivation of cocoa and kola nut, oil palm, yam in the east groundnut and cotton in the north.
   3. Natural Attachment or Historical Factor:-The growth of some empires in the past like Kano and Oyo empires favors high population density.
   4. Administrative Headquarters:-Some towns like Lagos, Kano, Ibadan, Enugu serve as administrative capitals that attracts people to the area.
   5. Employment Opportunities:-The Availability of Job in the in these towns also swells the population.
   6. Presence of Minerals:-The presence of minerals also contributes to high population density in these towns e.g Coal In Enugu.
   7. Presence of Industries: -The presence of Industries in Lagos, Ibadan, Sokoto provides Jobs for people.
   8. Presence of Social Amenities and Infrastructure:-The presence of these like pipe-borne water, schools, Electricity, Multipurpose hall, roads e.t.c In the town attracts high population.
   9. Commercial Activities:-Presence of Market and business transactions pulls people to these areas.
   10. Migration:-Rural-Urban Migration tends to Increase the population of these towns.
   
   
   Advantages of High Population Density.
   
   1. High Population provides a large labor force for Industries.
   2. High population is a source of a large market for the goods produced by industries.
   3. High population brings many people together and promote unity.
   4. It helps quick dissemination of Information
   5. High population help in defense of the area
   6. It helps in effective planning.
   
   
   Disadvantages of High Population Density
   
   1. Increase in the crime rate due to unemployment in most of the urban centers, there is a tendency to have a high crime rate or increase in crime rate.
   2. An increase in population leads to insufficient food supply.
   3. The high population leads to traffic congestion around Lagos.
   4. There is pressure on social amenities due to increase in population.
   5. The establishment of Industries in a densely populated area leads to the environmental population.
   6. Natural resources like fertile farmlands become over-exploited where there is high population growth in an area.
   7. An increase in Population leads to inadequate health services.
   8. Overpopulation brings about problems of housing.
   9. There is a problem with unemployment and underemployment.
   
   
   Areas of Low Population density
   
   1. The middle belt of Nigeria comprising Benue, Niger, Kogi, Kwara and Abuja areas.
   2. The Niger - Delta area e.g river state.
   3. The extreme North-East (Borno and Yobe)
   
   
   Reasons for low populated density
   
   1. Relief:-Presence of rugged highland in some of these areas promote low population.
   2. Drainage: The middle belt lies in the Niger--Benue valleys and delta areas which make settlement difficult because of the Niger River and Benue rivers.
   3. Unfavorable Climate: High temperature and low rainfall especially in Borno and Yobe state encourage a low population.
   4. Poor Soil:-Areas like Borno and Yobe state have poor sandy soil which does not support serious farming activities.
   
   
   Reasons for High Populated Areas
   
   1. Favorable Climate- The above areas have adequate rainfall which ensures the production of food, especially in the west and east and it is also favorable for human habitation.
   2. Employment Opportunities:-The availability of Jobs in these towns also swells the population.
   3. Presence of minerals:- The presence of minerals also contributes to high population densities of these town e.g coal in Enugu and tin in Jos
   4. Presence Of Industries: The presence of industries in Ibadan, Kano, Lagos, etc provide a job for people.
   5. Fertile Soil:-It favors the cultivation of cocoa and kola nut in the west, oil palm, yam cocoa in the East and groundnut and cotton in the North.
   
   
   Reason for Low Populated density in Nigeria
   
   1. Poor Soil: Area like Borno and Yobe state have poor sandy soil which does not support serious farming activities.
   2. Unfavorable Climate; High temperature and low rainfall, especially in Borno and Yobe, encourage low Population.
   3. Drainage:-The middle belt lies in the Niger Benue valley and delta areas which makes settlement difficult because of Niger, Benue river
   4. Relief: The presence of rugged highland in some of these areas promote a low population.
   5. Historical factors:-The trans-Sahara slave trade help in the development of the middle belt.

RELIEF IN NIGERIA

RELIEF IN NIGERIA



Relief refers to the surface feature of the land above the sea level. It relief of Nigeria can be grouped into 2 classes which are low lands and highlands.
LOWLANDS
It refers to the area below sea level.

AREA OF LOWLANDS IN NIGERIA

1. Coastal plain: Found in the southern part of the country. It contains sedimentary rocks of alluvial deposit.
2. Niger Benue plain/low kand: Found in the middle belt it contains sedimentary rocks of limestone, sandstone and shale.
3. Sokoto plain: found in the north-west of the country. It contains limestone and sandstone.
4. Chad plains: Found in the northeast of the country. It contains sandstone and day.

Importance of Lowland Areas.

i. It can be used for settlement
ii. It serves as a source of minerals e.g Crude Oil
iii. It is used for agricultural purpose
iv. It can be used for communication i.e Road construction, railway. Can also be built or constructed in lowland areas.
v. For grazing
vi. Rivers found in lowlands can provide Job Opportunity e.g Fish

Disadvantages

i. The areas are liable to flooding.
ii. A communication network is difficult as a result of heavy rainfall

HIGH LANDS

It refers to areas that are 300m above sea level.

Areas of Highlandland in Nigeria

1. The Northcentral highland:- It is the centre of northern Nigeria around Kano, Kaduna, Bauchi, Jigawa and Plateau e.t.c

Jos Plateau (about 1500m) is found in distant highland and it is a great hydrological centre of watershed with radical pattern of drainage in which river like river hadeja, Kaduna, Gana, Gongola etc take their source.
The highest point of Jos plateau is Shere Hill with over 1650m above the sea level.

2. The Western Highland; The western highland or uplands are found in the eastern part of Nigeria around Ondo, Oyo State, Kwara State and Osun State.

Importance hills in this area include Idanre Hills (50m above the sea level) Apata hill in Ado Ekiti 400 - 1000m above the sea level, Ekpeme hill in Edo State (350M - 600M) above the sea level and Kurukuru hills (500m above the sea level).
Some of the important rivers take the source from these highland river Ogun, river Osun, River Osse, River Owena e.t.c

The Eastern Land
This are found in the border between Nigeria and Cameroon. They represent the highest zone in Nigeria among the mountains are
i. Mandara (1200 -n1300m above the sea level)
ii. Biu Plateau (1000 -1500 above the sea level)
iii. Atlantika and Shebshi hills (1600 - 2000M above the sea level)
iv. Obudu and Oban hills (1200m above the sea level)
This area has a river like River Ngoda, River Goma etc.

The Eastern

This is found within the eastern region of Nigeria especially around Enugu and Nsukka. The major highland in this area is the Udi - Nsukka and Udi hills (300 - 600m) above the sea level.
River Anambra, River Imo, River Cross have the from the scape land.
Major Rock type in this highland are;

1. North Central, western highland Shebsi, Mandara mountain, Atlantic and Obudu and Obtain hill are made up of Igneous and metamorphic rocks.
2. Jos plateau is made of volcanic rocks
3. Udi hills are made up of sedimentary rocks

IMPORTANCE OF HIGHLAND

1. They serve as a source of mineral eg Tin in Jos Plateau, coal in udi hill
2. Highland help in the formation of Orographic or Relief Rainfall
3. Some Highlands serves as a defence
4. Transhumance is carried out in the high land region
5. Some highlands serves as tourist centre e.g Idanre hill and Obudu hill
6. They serve as a source of rivers.
7. Some mountain serves as windbreakers.

Disadvantages of Highlands

1. They prevent communication
2. They also prevent human habitation
3. Mountain or highland promote soil erosion
4. Mountain occupies good land which can be used for different purposes

CONCLUSION


In general, the topography of Nigeria consists of plains in the north and south interrupted by plateaus and hills in the centre of the country. The Sokoto Plains lie in the northwestern corner of the country, while the Borno Plains in the northeastern corner extend as far as the Lake Chad Basin. The Lake Chad basin and the coastal areas, including the Niger River delta and the western parts of the Sokoto region in the far northwest, are underlain by soft, geologically young sedimentary rocks. Gently undulating plains, which become waterlogged during the rainy season, are found in these areas. The characteristic landforms of the plateaus are high plains with broad, shallow valleys dotted with numerous hills or isolated mountains, called inselbergs; the underlying rocks are crystalline, although sandstones appear in river areas. The Jos Plateau rises almost in the centre of the country; it consists of extensive lava surfaces dotted with numerous extinct volcanoes. Other eroded surfaces, such as the Udi-Nsukka escarpment (see Udi-Nsukka Plateau), rise abruptly above the plains at elevations of at least 1,000 feet (300 metres). The most mountainous area is along the southeastern border with Cameroon, where the Cameroon Highlands rise to the highest points in the country, Chappal Waddi (7,936 feet [2,419 metres]) in the Gotel Mountains and Mount Dimlang (6,699 feet [2,042 metres]) in the Shebshi Mountains.

VEGETATION IN NIGERIA

VEGETATION IN NIGERIA

The geographical area called Nigeria has a total land area of 983,213 km2 with over 180 millionpeople living in it. The country is covered by three major types of vegetation which include forests, savannas, and montane land.

In this post, we'll find out what these vegetation types mean and we'll further divide them into other zones.

Vegetation can be defined as the association of plants. Vegetation is also an area of land on which different species of plants can grow.

In Nigeria, vegetation formation is divided into three major zones.

1. The Forest Vegetation
2. The Savanna Vegetation
3. The Montane Vegetation

Both forest and savanna can be sub-divided into different belts.
Forest Vegetation: At the northern part of this region is freshwater swamp. There is also the saltwater mangrove swamp as well as the rain forest which is located north of this swamp.
i. Mangrove Swamp Forest
ii. Fresh Water Forest
iii. Equitorial Rain Forest
Savanna Vegetation: Savannahs are areas with insignificant tree cover with grasses and flowers found between these trees.
i. Guinea Savanna
ii. Sudan Savanna
iii. Sahel Savanna
Mangrove Swamp Forest
This vegetation is found mainly in Delta and coastal areas like Port Harcourt, Warri, Uyo and Calabar.
Characteristics of Mangrove Swamp

1. It has a tail, woody Mangrove tree
2. It has a serial root
3. It has evergreen trees with broad leaves
4. Trees found include mangrove raffia palm
5. Aquatic Organism are found
6. Water is salty or blackish in nature
7. No natural forest vegetation apart from the presence of water jacinth
8. It is found in the north of the Atlantic ocean.

Importance
-Raffia is used for making basket, bags, broom, etc
- Mangrove trees are used for boat building
-Farming activities such as swamp rice cultivation are embarked.
THE FRESHWATER SWAMP FOREST
This type of forest is found further include mainly in Niger Delta, Lagos and along river valleys.
Characteristics

1. It has raffia palms
2. It has climbing plants and freshwater ferms
3. Aquatic animals are found
4. Its water is not salty

Importance

1. The mangrove tree is used for supporting the roof of coal mines
2. It serves as fuel
3. An acid called thiamin can be extracted from the trees. This is used for leather works.
4. The trees is used for the construction of railway sleepers.

RAIN FOREST
It is found in the southern part of Nigeria in Benin, Sapele, Akure, Ibadan, Abeokuta, Aba etc.
Characteristics

1. It has tall trees with buttress roots, evergreen, and broad leaves
2. Trees exist different height, storage or layers i.e bottom or lower, middle and upper layers.
3. Presence of little undergrowth due to the canopy of the forest
4. Presence of climbers, creepers, epiphyte and parasitic plants
5. It has numerous heterogeneous species of trees like Iroko, obeche etc
6. Plants species are not in pure stand
7. Trees are generally evergreen

Guinea Savanna
The savanna is found in Ilorin, Lokoja, Markudi, Abuja.
Characteristics
-It is the largest of all the vegetation belts in Nigeria.
-Presence of all the vegetation
-The trees are scattered and deciduous (Shed Leaves)
-Important trees include locust bean trees, shead tuber etc
-Rainfall is about 1000mmper annum
-Rainfall duration is between 5-6 months
Sudan Savanna
The vegetation belt is found in Sokoto, Kano, Kaduna, Dutse, Bauchi etc
SUDAN SAVANNA
The vegetation belt is found in Sokoto, Kano, Kaduna, Dutse, Bauchi etc.
Characteristics
-Amount of rainfall is 600mm per annum
-Rainfall duration is about 4months
-Animals like herbivores and Carnivores are found
-It has short numerous grasses
-Presence of scattered and short deciduous plant
-Plants species include Acacia, suki cotton, plants, baobab
-Some trees have thorns while others have barks
-Some trees wither in the dry season and sprout at the beginning of the rainy season.
Sahel Savanna
It is found in Maduguri and Damaturu.
Characteristics
-It has short scanty grasses
-Presence of short and tough shrubs.
-It has many drought resistance and scattered plants
-Popular plants include Acacia, date palm, baobab
-Rainfall is less than 456mm per year
-Trees found are drought in resistant
Montane Vegetation
This is found in Jos.
Characteristics
-It is associated with highland
-It has various trees at the windward side
-It has grasses at the Leeward Side/rainfall shadow
-Wind ward is the side where wide seconded a mountain
Shrubs: A plant that is cut and planned in order to decorate.
Characteristics
-Presence of short scattered trees.
-It combines tall trees at the foot and short or peak summit
Summary
These vegetative zones are also known for their economic benefits. 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 a roofing material.
Additionally, the juice of the palm wine is used to produce wine while cash crops like cocoa, peanuts, cotton, and many tropical crops are foreign earners

RESPIRATORY SYSTEM

RESPIRATORY SYSTEM

This involves the process by which oxygen is taken into the body cells(s) and used to break down food particles in order to release energy. The intake of oxygen into each cell simultaneously accompanied by the removal of carbon dioxide and some molecules of water through the same rate (exchange surface)

RESPIRATION IN ANIMALS
Respiration in Animal is purely aerobic hence; all animals need a quick means of obtaining oxygen for their respiratory activities and this has led to the evolution of respiratory organs. There are four (4) different types of organs of surface which animals use for gaseous exchange and these are

1. Body Surfaces
2. Trachea
3. Gills
4. Lungs

Characteristics or features of a Good Respiratory surface

1. Presence of large surface area
2. A good respiratory surface must be well vascularized i.e supply of blood
3. It must have thin epithelium i.e Surface living
4. It must have a ventilation system
5. A good respiratory surface must always be moist etc

Respiratory Surfaces

1. Body Surface: This is used for gaseous exchange in the lower animal such as the moners, Protist (Amoeba) some nematodes and annelids. They are able to achieve this due to their small sizes which made them have a large surface area per volume ratio. Hence, Oxygen easily diffuses from their environment across the cell membrane into their cytoplasm for use. Gaseous exchange through the body surfaces is also found in some nematodes in which oxygen diffuses in their body through their moist. This type of respiration in them is called Cutaneous respiration.
2. The Trachea: The trachea is a system of branching tubes that is sub-divided into smaller units called tracheoles and this amplifies through the body of the animals. The trachea system opens through the ventilation structure called spiracles. Which line up at either side of thoracic and abdominal cavities in pairs. When the concentration of carbon iv oxide is high in the body tissues of arthropods, the spiracles valves opens widely and allows an inflow of air through it into the trachea, Carbon iv oxide also flows out simultaneously.

Diagram of a Trachea

3. The Gills
This is a highly braced respiratory growth with flat surface used for gaseous exchange in the aquatic environment.
Diagram of a Gill

The Gills
The gills can either be external or internal. External gills are found in tadpoles and slung while the internal gills are found in fish and some crustaceans, the external gills project out of the body of the organism and they are not covered by the operculum plate (Operculum) However, they are linked with the circulatory systems.

This is very important unlike the internal gills which are enclosed in a special chamber in the head region and projected by the operculum plate hence, internal gills are well protected from mechanical injury. Additionally, they don't hinder or prevent the free movement of the animal through the water.

The gills are made up of folding unit which is prevented from collapsing on one another by the density of the water if piration occurs when the fish opens its mouth and lowers the floor of the buccal cavity during which their operculum is tightly closed, water then rushes into the mouth and the dissolved oxygen diffuses across the surface of the gills into the circulatory system.
Expiration also occurs when then fish closes its mouth and the operculum plate is opened the carbon dioxide produced after respiration then flows out of the opercula chambers.

Exchange of gases takes place on the surface of the gills arch serves to hold the gills rackers functions in sieving out particles from the inflowing water to prevent their entry into surfaces of the gill filament thereby causing damage. The sieved out particles, in turn, serve as food for the fish.
4. The lungs - The lungs are the two most highly vascularised internal gaseous exchange surfaces used by terrestrial higher animals. The lungs is surrounded by a membrane called a pleural membrane and they are protected by the rib case. Air from outside is suckled through the mouth (Buccal Cavity) or the nose (nasal cavity) into the pharynx from where the air direct to the larynx.
Functions of some Respiratory organ

1. The Rib cage

a. It protects the lungs
b. It provides a means of breathing
2. Intercoastal muscle
a. It brings about the movement of ribs
3. Pleural Cavity
a. It protects the lungs
b. It provides a means for breathing
4. Diaphragm
a. It Protects the lungs
b. It brings about movement of the rib during breathing
5. Lungs, Bronchia and Trachea
They are reinforced with cartilage to prevent pipes from collapsing when air pressure within them is low.
Composition of Inhaled and Exhaled air
Gas                           Inhaled air                  Exhaled air
Oxygen                      21% 16%
Carbon dioxide           0.03%                        between 4 to 6%
Nitrogen                      78%                           78%
Water Vapour           Variable                         Saturated

NOTE: During normal, inspiration or respiration about 500cm3 of air goes in or out of the lungs. The air is known as tidal air, However, the lung usually has some leftover the air in it and the air is known as residual air.

After a normal Inspiration, more can still be possibly taken into the lung into its fullest capacity. This volume is known as a total living capacity.

ENERGY TRANSFORMATION

ENERGY TRANSFORMATION

The total energy from the solar energy that reaches the earth's surface only about 1% of it is available by the primary producer.
These primary producers transform a small % of light energy into chemical energy in food during photosynthesis, while the larger part is lost as heat energy during the various chemical reaction.
The plant uses most of the food energy for its metabolic activities with some lost as heat while only about 10% of it is passed to the primary consumer.
The primary consumer also Incorporate some more energy into their tissue and pass about 20% of energy to the next level unit until it reaches the tertiary consumer. When these die, the energy in the food stored in its body is eventually in the atmosphere as heat by the decomposers.

NUTRIENT CYCLING

Unlike energy which eventually lost to the atmosphere heat, the nutrient are always recycled in an ecosystem.
The product manufacture organic materials, these are eaten and assimilated by the consumer eventually at death, the organic matter that has been assimilated into the bodies of the consumer are broken down in organic materials by the action of the decomposers and these can be reabsorbed by the producers.
The most important of these Inorganic nutrients are Carbon, Nitrogen, Water and Oxygen.


The Carbon Cycle



The atmosphere contains a pool of CO2 which is being removed continuously by green plants for the process of photosynthesis. In the same way, the dissolved CO2 in the aquatic environment is absorbed and used by the photosynthetic Phytoplanktons.
This CO2 is manufactured into complex sugar e.g starch in the plant tissues, and the plants are eaten by the animals which also Incorporate the nutrient into their own tissues.
However, during respiration, both the plants are eaten by the animal which also Incorporates the nutrient into their own tissues.
However, during respiration, both the plants and animals break down the sugar to liberate carbon dioxide which returns back to the atmosphere and water, so also the plants and animals die, the decomposer act on their remains and bring about decay which sets free the trapped carbon dioxide to return back to the atmosphere.
In the situation whereby the plants and animals remain are partly decayed, these accumulated in the soil over many years to form fossil fuels like coal, peat, and petroleum.
When these fossil fuels are burnt by man to obtain energy for various purposes there is the release of CO2 into the atmosphere.
In the aquatic environment, the shells of many marine animals also release some quantity of CO2 into the water when the animals die.
Importance of Carbon In Nature
Carnon is very important in nature because it is carbon compounds that serve to be reservoirs of energy from which living organisms fetch along the food chain.

Oxygen Cycle

Just like there is a pool of oxygen gas, oxygen is removed from the atmosphere by both plant and animals as well as aerobic micro-organisms for the process of respiration and decay.
In like manner, fuels also use oxygen during combustion. However, an equivalent amount of oxygen is returned back into the atmosphere through the process of photosynthesis by green plants.


Oxygen In Air & Water

Carbon - Oxygen In Nature

The Oxygen used up in the atmosphere through respiration and combustion is replenished through the process of photosynthesis and also the oxygen in the atmosphere is maintained at a constant level of about 20% of the air.
However, pollution of water bodies leads to an increase in activities of the decomposer as well as aerobic micro-organism and these leads to oxygen depletion which affects the survival of the aquatic organisms.
Carbon is being absorbed from the atmosphere by the process of photosynthesis and given to the air by the process of respiration, decay, and combustion. This is direct of the opposite balance in nature. Human activities most especially combustion tend to increase in the quantity of carbon-dioxide added to the atmospheric and with time, excess of atmospheric carbon dioxide may lead to phenomena called the "greenhouse effect" these occur when too much heat energy from the sun is retained in the atmosphere.
This results in the global warming of the earth and these affect the balance nature of the earth's ecosystem.

The Water Cycle




The largest quantity of water circulates within the non-living environment. While only a small proportion is recycled through the living components of the ecosystem. Water molecules from the water bodies and the soil evaporates and form the clouds which condense and precipitate into rain and snow that goes back into the soil and water bodies.

Water enters into the biotic component of the ecosystem when the plant absorb water from the soil or the animals take in water from their food and drink. Only a small part of the water absorbed by plant is used for the process of photosynthesis but the larger part is lost through the process of transpiration. Some little quantity is lost during respiration and decay.

DECOMPOSITION IN NATURE

The decomposers are the saprophytic organisms majorly bacteria and fungi which are involved in breaking down the complex organic molecules into simple inorganic molecules.
These are very important in the cycling of nutrients in an ecosystem by connecting the living component. By their action, they bring about decomposition of the dead organism or their excreta or (like feaces and urine by secreting digestive enzymes on their food materials into simple fluid-like Inorganic substances or nutrients which can be absorbed by decomposers but the larger % is lost into the soil water and air. Some Inorganic nutrient are released by the action of the decomposer includes Ammonia, water vapor, sulphate, phosphate, etc.
These Inorganic substances can then be absorbed by the autotrophic organism (i.e photosynthetic, chemosynthetic, green plant) to manufacture energy, rich food that supports life.
Important Of Decomposers

1. Decomposers help in the recycling of nutrients and thus make the nutrient available for the plant to produce energy, rich food that sustain life therefore, the decomposer allows the ecosystem to be a functioning one.
2.  The decomposers prevent the accumulation of the dead bodies and excreta from the living organism.