Deforestation and Desertification

FIRST TERM E-LEARNING NOTE

SUBJECT: BASIC SCIENCE 

CLASS: JSS 3

WEEK THREE

DESERTIFICATION AND DEFORESTATION

CONTENT

• Definition of Deforestation
• Causes of Deforestation
• Effects of Deforestation
• Control of Deforestation

DEFINITION

Deforestation is the continuous removal of trees without replacing or replanting them. Deforestation is also the permanent destruction of forest in order to make land available for other uses.

CAUSES OF DEFORESTATION

1. Removal of trees to make land available for the construction of roads, building of houses and industries, recreational centres and so on.
2. Indiscriminate logging by poachers for industrial purposes like the production of paper, furnitures, sculptures etc.
3. Felling of trees to make wood available for domestic purposes like cooking.
4. Burning of forest for hunting and farming.
5. Natural causes like forest fire during thunderstorm or landslides can also lead to loss of forest trees.

EVALUATION

1. What is deforestation?
2. State five causes of deforestation.

EFFECTS OF DEFORESTATION

1. Deforestation leads to the loss of of wildlife and biodiversity. This means that wild animals in the forest like monkeys, gorillas etc, will gradual die off.
2. Deforestation contributes to climatic change and increase in global warming.
3. Deforestation lead to the lost of habitat of so many species of animals especially birds.
4. Deforestation lead to decrease in atmospheric oxygen and increase in CO₂. This means that plants and animals are in danger because there will less oxygen to breathe in.
5. Deforestation leads to flooding and erosion.
6. Deforestation may lead to starvation and homeless. This is because there will be no food or wood to build shelter.
7. Deforestation may lead to economic loss if forest raw materials are no longer available for industry to use or export.

WAYS TO CONTROL DEFORESTATION

1. Afforestation: This is the planting of trees in places where they are not planted before. Afforestation helps to bring forest condition to places where they do not exist before. An example of afforestation is the “Plant A Tree” initiative.
2. Reforestation: This is the replanting of trees to replace those trees that have been removed from the forest.
3. Government should make laws against indiscriminate poaching and logging.
4. Government should make laws against bush burning.
5. The use of forest guards to keep trespassers away from the forest.

EVALUATION

1. State four effect of deforestation.
2. State four ways to control deforestation.

IMPORTANCE OF FOREST

1. The forest provides raw materials like timber, latex, and medicinal extracts etc, to industries.
2. Trees of the forest help in purifying the atmosphere by removing excess CO₂ from the atmosphere for photosynthesis.
3. The forest is the home of many animals which provides hides and skin for us to make clothes, bags, shoes and so on.
4. The availability of forest provides employment for a lot of people.
5. The presence of trees slows down erosion and desert encroachment.

EVALUATION

What are the importance of forest to man.

CONTENT

• Definition of Desertification
• Causes of Desertification
• Control of Desertification

DESERTIFICATION

A desert is a large area of land with little or no rainfall where very few plants grow. Desertification is the process of making a non desert area a desert. It is the spread of desert to places where they previously do not exist. In Nigeria, about 50% to 75% of the northeast and northwestern states are deserts. State like Bauchi, Bornu, Gombe, Taraba, Jigawa, Kano, Katsina, Kebbi, Sokoto, Yobe and Zamfara all have deserts. Like most environmental hazards, desertification is majorly influenced by climatic change and human activities.

LIST OF SOME DESERTS IN AFRICA

1. Sahara desert is the largest hot desert found in North Africa.
2. Namid desert found in Southern Africa.
3. Kalahari desert also found in Southern Africa.

CAUSES OF DESERTIFICATION

1. Frequent bush burning.
2. Water impoundment.
3. Increased salinity.
4. Climatic change.

EVALUATION

1. What is a desert?
2. What is desertification?
3. Mention four causes of desertification.

CONTROL OF DESERTIFICATION

1. Planting of leguminous crops to restore soil fertility.
2. Digging of artificial grooves to retain rainfall and trap wind blown seed.
3. Planting of trees and cover crops.
4. Public awareness on the need to prevent desertification.
5. Use of proper farming method can help prevent desertification.

EVALUATION

Mention four ways to control desertification.

GENERAL EVALUATION

1. What is deforestation?
2. List three major deserts in the world and their location.
3. List five ways to control erosion.
4. What is a skeleton?
5. List the planets in our solar system according to their distance from the sun.

READING ASSIGNMENT

Basic Science Made Easy for JSS Three by F.I. Kehinde et al. Chapter 4. Page 12

WEEKEND ASSIGNMENT

1. One of the method of control of the deforestation include bush burning  B. Logging  C. Afforestation  D. Clean weeding
2. The largest desert in the world is found in Australia  B. South Asia
3. North Africa D. Western Europe
4. One of the following is not a method of controlling desertification.
5. Overgrazing B. Afforestation C. Planting of cover crops  D. Public awareness
6. One importance of forest trees is that they Purify the atmosphere
7. cause soil erosion C. destroy the ozone layer D. lead to loss of biodiversity
8. The planting of trees where they do not previous exist is called
9. Deforestation B. Desertification C. Afforestation  D. Reforestation

THEORY

1. What are the benefits of forest to man?
2. Explain how increased salinity can cause desertification

SOIL EROSION

Soil erosion is the wearing away and loss of soil from an area. Soil erosion is the washing away of soil by heavy rain or wind resulting in formation of gulley and landslides and leaving behind barren rocks and slits on which plants can no longer grow. Soil erosion poses serious to agriculture as it wash away the nutrient from the topsoil.

TYPES OF EROSION

Based on the cause of erosion, we have:

Water erosion: This is the erosion caused as a result of heavy rainfall or flood which wash away the soil on slopes. Constant flow of water create gullies over a long time. When rain falls on sloppy ground the water runs off thereby washing away a large portion soil and also breaking down rocks in a process called weathering.

Wind erosion: This the erosion caused by fast moving wind which exposes the top soil and carry them away. Wind erosion can be controlled by planting trees along the wind path. These trees serve as windbreaker

HUMAN ACTIVITIES THAT CAUSE EROSION

Burning of bush: The deliberate or accidental burning of bush destroys the soil structure and exposes it to erosion and high temperature.

Farming: The cutting of trees and clearing of farmlands exposes the soil to erosion

Building of house and industries: The clearing of land before the building of houses promote erosion.

Growth of town: Development of town leads to the exposure of the soil surfaces which can easily be washed away.

Construction of roads: The construction of new road leads to the breaking of soil structure which make it easy for soil to be washed away.

EFFECTS OF EROSION

1. It reduces soil fertility.
2. It damages road and soil surfaces.
3. It destroys farmland and farm produce.
4. It may lead to lose of buildings.
5. It leads to loss of lives through accident and building collapse.

CONTROL OF EROSION

1. Indiscriminate burning of bushes should be stopped.
2. Plant of trees and cover crops.
3. The practice of mulching in which cut grass residue are spread over the soil surface under a growing crop which retains moisture, reduces weeds and prevent exposure of the soil surface thereby reducing soil erosion.
4. Construction of terraces on sloppy land.

METHODS OF PREVENTING SOIL EROSION

1. Wind erosion can be prevented by planting cover crops, grasses and belt of trees which serves as wind breakers.
2. Water erosion and flooding can be prevented through proper canals and drainage channels to lead water away in to rivers.
3. Gully erosion can be stopped by small dams with stones and sticks along the gullies in order to capture soil that is being washed away.
4. Terrace should be build to prevent erosion. Terraces are barriers constructed along contours of the land which hinders the rapid flow of water down the slopes.

GENERAL EVALUATION

1. What is flood?
2. What are the activities of man that contributes to flooding?
3. What is power?
4. What is puberty?
5. Explain what you understand by “teetotalism”
6. What is pregnancy?

[mediator_tech]

WEEKEND ASSIGNMENT

1. The overflowing of rivers as a result of continuous rainfall leads to
2. erosion B. deforestation C. flooding  D. drought
3. Which of the following will help to control flooding? Overgrazing
4. Deforestation C. Damming of rivers D. Dumping of refuse
5. Which of the following does not contribute to flooding?
6. Blocked drainage B. Overflowing rivers C. Adequate drainage system
7. Loss of lives
8. Which of the following is a consequence of flooding? Growth and development   B. Increased fertility  C. Destruction of livestock  D. Provision of food
9. Flood is a ___ occurrence. natural  B. Man-made  C. Phenomenal
10. Economical

THEORY

1. List five things you can do to prevent flooding in your immediate environment.
2. What are the environmental and economic impacts of flooding?
3. Mention five ways to prevent erosion?

[mediator_tech]

1. **Question 1:** A forest is a large area of land covered with many __________ and various types of vegetation.
a) Rivers
b) Trees
c) Mountains

2. **Question 2:** The upper layer of a forest formed by the branches and leaves of tall trees is called the __________.
a) Canopy
b) Understory
c) Forest Floor

3. **Question 3:** Deforestation is the widespread clearing, removal, or destruction of __________.
a) Animals
b) Forests
c) Rivers

4. **Question 4:** Trees play a crucial role in regulating the climate by absorbing __________ during photosynthesis.
a) Oxygen
b) Carbon dioxide (CO2)
c) Nitrogen

5. **Question 5:** Loss of __________ is one of the significant effects of deforestation, as many species lose their homes.
a) Freshwater
b) Biodiversity
c) Oxygen

6. **Question 6:** The ground level of a forest is called the __________.
a) Understory
b) Canopy
c) Forest Floor

7. **Question 7:** __________ is one of the main causes of deforestation, as it involves cutting down trees for human use.
a) Planting new trees
b) Reforestation
c) Logging

8. **Question 8:** Trees and their root systems help prevent __________, which can be increased by deforestation.
a) Soil erosion
b) Water pollution
c) Air pollution

9. **Question 9:** Forests provide various resources, such as timber, food, and __________ for human use.
a) Electricity
b) Medicinal plants
c) Metal ores

10. **Question 10:** __________ play a crucial role in the water cycle by absorbing rainfall and releasing it slowly.
a) Rivers
b) Mountains
c) Forests

11. **Question 11:** Indigenous communities depend on forests for their livelihoods and __________ practices.
a) Urban
b) Cultural
c) Agricultural

12. **Question 12:** Deforestation leads to the release of __________, contributing to global warming.
a) Oxygen
b) Carbon dioxide (CO2)
c) Nitrogen

13. **Question 13:** Forests are diverse ecosystems with many plant and __________ species.
a) Human
b) Animal
c) Ocean

14. **Question 14:** The main reason for deforestation is the need for land for agriculture and __________.
a) Mining
b) Fishing
c) Water supply

15. **Question 15:** The upper layer of the forest, called the canopy, acts as a protective cover, shielding the forest floor from excessive __________.
a) Rainfall
b) Sunlight
c) Wind

Hello class! Today, we are going to learn about forests. So, what is a forest?

A forest is a large area of land that is covered with many trees and various types of vegetation. It’s a natural ecosystem where plants, animals, and microorganisms live and interact with each other. Forests can be found in different parts of the world and come in various types, such as tropical rainforests, temperate forests, and boreal forests.

Let’s break down some key characteristics of forests:

1. Trees: The most dominant feature of a forest is the presence of a large number of trees. These trees can be of different species and sizes, and they play a crucial role in maintaining the ecosystem’s balance.

2. Biodiversity: Forests are incredibly diverse environments, home to a wide variety of plants, animals, insects, and other living organisms. The interactions between these species are vital for the health and sustainability of the forest ecosystem.

3. Canopy: The upper layer of a forest, formed by the branches and leaves of tall trees, is called the canopy. It acts as a protective cover, shielding the forest floor from excessive sunlight and regulating temperature and humidity.

4. Understory: Beneath the canopy, there is a lower layer known as the understory. Here, you will find smaller trees, shrubs, and young saplings, along with various plants adapted to lower light conditions.

5. Forest Floor: The ground level of the forest is called the forest floor. It is often covered with fallen leaves, decomposing plant matter, and soil that provide essential nutrients for the growth of plants.

6. Wildlife Habitat: Forests provide a habitat for numerous animals, including mammals, birds, reptiles, amphibians, and insects. Some species are specific to certain types of forests and rely on them for food, shelter, and breeding.

7. Ecological Importance: Forests play a crucial role in maintaining the Earth’s ecological balance. They help regulate the climate by absorbing carbon dioxide during photosynthesis and releasing oxygen, making them essential in the fight against climate change.

8. Human Benefits: Forests are valuable to humans in many ways. They provide us with timber, food, medicinal plants, and various other resources. Moreover, forests offer recreational opportunities, like hiking, birdwatching, and camping.

It’s essential to recognize the importance of forests and work towards their conservation and sustainable management to protect the environment and all the living beings that depend on them. So, let’s cherish and preserve these beautiful natural ecosystems for generations to come.

Deforestation refers to the widespread clearing, removal, or destruction of forests, typically for various human activities such as agriculture, logging, urban expansion, mining, and infrastructure development. It is the process by which forests are permanently converted into non-forest lands, leading to the loss of trees and the disruption of the forest ecosystem.

Key points about deforestation:

1. **Causes:** Deforestation is primarily driven by human activities. Some common reasons for deforestation include the need for land to grow crops, establish livestock pastures, build settlements, and extract valuable natural resources like timber and minerals.

2. **Environmental Impact:** Deforestation has severe environmental consequences. Trees play a crucial role in regulating the climate by absorbing carbon dioxide (a greenhouse gas) during photosynthesis. When trees are cut down or burned, the stored carbon is released back into the atmosphere, contributing to global warming and climate change.

3. **Loss of Biodiversity:** Forests are incredibly biodiverse ecosystems, home to countless plant and animal species. When forests are destroyed, many species lose their habitat, leading to a decline in biodiversity and, in some cases, species extinction.

4. **Soil Erosion:** Trees and their root systems help stabilize the soil, preventing erosion caused by wind and rain. Deforestation can lead to increased soil erosion, degrading the land’s fertility and causing sedimentation in rivers and streams.

5. **Disruption of Water Cycle:** Forests play a crucial role in the water cycle. They absorb rainfall and release it slowly, helping to maintain steady water flow in rivers and underground aquifers. Deforestation can disrupt this cycle, leading to altered water availability and potential water scarcity.

6. **Impact on Indigenous Communities:** Deforestation often affects indigenous and local communities who depend on the forest for their livelihoods and cultural practices. Their traditional way of life can be threatened when their lands are cleared or exploited for resources.

7. **Loss of Economic Opportunities:** While deforestation may provide short-term economic gains through resource extraction and agriculture, it can lead to long-term negative economic impacts. Loss of ecosystem services, such as clean water, climate regulation, and ecotourism, can have far-reaching consequences for local and global economies.

8. **Efforts for Conservation:** Many organizations and governments are working to address deforestation through conservation efforts, reforestation (planting new trees), sustainable forest management, and promoting responsible practices in industries that rely on forest resources.

Addressing deforestation is crucial for mitigating climate change, protecting biodiversity, and ensuring a sustainable future for our planet and all its inhabitants. It requires a collective effort from governments, businesses, communities, and individuals to find sustainable solutions and balance human needs with environmental preservation.

[mediator_tech]

1. **Climate Change:** Deforestation is a major contributor to climate change. Trees absorb carbon dioxide (CO2) during photosynthesis and act as a carbon sink, helping to reduce greenhouse gases in the atmosphere. When forests are cleared, this stored carbon is released back into the air, increasing the concentration of greenhouse gases and contributing to global warming and climate instability.

2. **Loss of Biodiversity:** Forests are incredibly diverse ecosystems, home to a vast array of plant and animal species. Deforestation leads to habitat destruction, causing many species to lose their homes and eventually leading to a decline in biodiversity. Some species may even face the risk of extinction due to the loss of their natural habitats.

3. **Soil Erosion and Degradation:** Trees play a critical role in preventing soil erosion. Their root systems help bind the soil together, reducing the impact of wind and rain. When trees are removed, the soil becomes more susceptible to erosion, leading to its degradation and reduced fertility. This can result in land degradation and decreased agricultural productivity.

4. **Disruption of Water Cycle:** Forests are vital in regulating the water cycle. They absorb rainfall, reducing runoff and facilitating a steady flow of water into rivers and aquifers. Deforestation disrupts this cycle, leading to altered precipitation patterns, reduced water availability, and potential water scarcity in the affected regions.

5. **Loss of Livelihoods and Indigenous Communities:** Many indigenous and local communities depend on forests for their livelihoods, cultural practices, and traditional knowledge. Deforestation often leads to the displacement and marginalization of these communities, disrupting their way of life and threatening their cultural heritage.

It’s important to recognize these effects and take action to curb deforestation through sustainable practices, reforestation efforts, and the protection of natural habitats. Conserving forests is crucial for maintaining ecological balance, safeguarding biodiversity, and ensuring a sustainable future for both human and non-human life on Earth.