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Lesson Note

Subject: BST

Topic: Environmental Harzards III

Subtopic: Bush Burning and Desertification

Class: JS3

Term: first

Objectives: by the end of this lesson, learners should be able to:

  1. Define the term Bush burning;
  2. State practices that influence Bush burning;
  3. Discuss the effects of Bush burning;
  4. Suggest regulation against Bush burning.

Lesson Summary/Discussions

Bush Burning
The term ‘Bush burning’ can be defined as an act which involves the setting of fire on bush to clear out the vegetation.

Practices that Influence Bush Burning

  1. Many people set fire deliberately on bush for the purpose of hunting or for the purpose of making new grasses to grow up for cattle to feed on.
  2. Bush burning could even be accidental, either by wind spreading the fire used for cooking to a bush or by cigarette fire dropped carelessly around the bush. No matter the cause of the bush burning, it exposes the surface of the soil to high temperature via the sun.
  3. Livestock Disease Management: bush burning is the most common traditional way of controlling insects by some locals such as the cattle rearers who habitually use moderate, localised fires to fight off insects and harmful pests from the homes and “kraals”, we must get it clear that when they set fire, their intention is not to generate heat, but to send out dense smoke that repels the ticks, ants, bugs, bees, locust, rodents and reptiles. But do we now say that this reason is enough to encourage bush burning?
  4. Easy Clearing of Farmland: Some farmers opt for bush burning (burn their farmlands) in other to save time that is, for easy clearing of the land for quick cultivation of crops. This also conserves energy for the farmers/land users. Over time it has been observed that bush burning clears (removes) the grasses, weeds (vegetation) better than cutting with a cutlass. However, this tends to be a disadvantage more than an advantage since soil organisms and nutricnts are affected.

Effects of Bush Burning
The negative inpact of bush burning can never be over emphasized especially during the hot season. Apart from environmental pollution and health hazards, bush burning obviously causes immense catastrophes in many quarters such as the suffocating experience felt by people due to the huge smoke soaring in the air during the heat, and the pollution of the ozone layer of the environment. In this regards the menace is of double tragedy in the sense that while the heat is unbearable, bush burning
fires also heat up the soil thereby blazing up its nutrients including the fertilizer elements.

Furthermore, the fire is smouldering and all the components of the plants as well as the grasses that are useful in conserving the forest, wild life and small animals are being destroyed in large proportion.
Based on the new issues in soil fertility management, the menace of bush burning should be adequately looked into with a view of discouraging it especially in hotter regions.

Bush burning and the other environmental hazards are threatening the existence of arable land and there is the fear that if the abusers are not checked and brought under control, the people may suffer long term hunger.
The long term effects of fire despite its widely acclaimed advantage are still very much devastating. A little portion lit can lead to an uncontrollable spread that engulfs acres of grassland within hours.
Most parts of the north are adversely affected by the menace. Large – scale fires shrink the radi of the grazing land, thereby exacerbating (making worse) the stressful conditions under which the animals dwell.

Some other effects of bush burning are:

  • Bush burning reduces the water holding capacity of the soil.
  • exposes the soil to erosion and leaching.
  • It leads to land degradation, flooding, erosion, deforestation, descrtification and climatic drought.
  • It disrupts the ccosystem balance.
  • It disrupts the natural food chain.
  • It destroys many micro-organisms.
  • It pollutes the atmosphere with smoke.
  • The ash produced gives the soil a slightly alkaline nature.

Evaluation

  1. Define the term Bush burning.
  2. State practices that influence Bush burning.
  3. What are the effects of Bush burning?
  4. Suggest regulation against Bush burning.

See previous lessons in BST

Environmental Harzards IV: Desertification

Objectives: by the end of this lesson, learners should be able to:

  1. Define the term desertification;
  2. Identify geographical zones prone to desertification;
  3. Describe different human practices that leads to desertification;
  4. Identify various methods for control of desertification.

Lesson Summary

Desertification

Deserts are very dry places. They receive very low rainfall and in hot areas evaporation causes high
water loss. There are many types of deserts with a variety of climates (hot, cold), locations (inland, coastal), appearances (sandy, rocky), and levels of vegetation (low, low ground cover, shubby bushes).
Hot deserts which are located near the equator, have hot days and cold nights because of the lack of the protective cloud cover.
Cold deserts, away from the equator and usually in the centre of continents in high mountains areas, have winters of ice and snow.
Definition: Desertification can be defined as the extreme deterioration of land in arid and dry sub- humid areas due to loss of vegetation and soil moisture. It can also be defined as the gradual transformation of once productive land into land incapable of supporting plant growth.

Some Human Practices that can Lead to Desertification
Desertification results chiefly from man-made activities and influenced by climatic variations.
Some causes of desertification include:

  1. Over grazing.
  2. Over drafting of ground water.p
  3. Over cultivation.
  4. Diversion of water from rivers for human consumption and industrial uses.
  5. Increased soil salinity.
  6. Deforestation.
  7. Global climatic change.
  8. Bush burning

Effects of Desertification
The following are some effects of desertification:

  1. lt reduces wild life population in the areas concerned.
  • lt hinders microrganisms activities in the soil.
  • It reduces the humuS conlent of the soil.
  • It causes deforestation.
  • It results in loss of soil nutrients through leaching and erosion.
  • It causes the drying up ot rivers, streams, lakes etc.
  • It reduces water percolation since the humus and dead leaves are absent.

Combating Desertification / Control Measure
Desertification can be combatted through the following ways:

  1. Creating awareness on the threats posed by it to the rural Africans living in the desertified areas.
  • Afforestation programmes
  • Environmental laws with penalties should be enacted to prevent people from defaulting.
  • Evolving means of transferring appropriate technological skills in desert control.
  • Providing professional consulting service and delivery of expert’s advice in the areas of desertification.

See previous lessons in BST

Evaluation

  1. Define the term desertification.
  2. Mention the geographical zones prone to desertification.
  3. Describe different human practices that leads to desertification.
  4. Mention the various methods for control of desertification.

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