The Bio Brief

When forests are cut down, it does not affect only trees. It affects climate, soil, water, animals, and humans. Let us understand step by step.

 Main Consequences of Deforestation

1.Increase in Temperature (Global Warming)

• Trees use carbon dioxide (CO₂) during photosynthesis.
• When trees are fewer → less CO₂ is used.
• Extra CO₂ traps heat in the atmosphere.

 Flow Chart

Deforestation
     ↓
Fewer trees

↓

More CO₂ in air

↓

Heat gets trapped

↓

Rise in Earth’s temperature (Global warming)

 Result: Climate becomes hotter.

2. Disturbance in the Water Cycle → Less Rainfall

Trees release water vapour through transpiration, which helps in cloud formation.

 Flow Chart

Deforestation

↓

Less transpiration from trees

↓

Less water vapour in air

↓

Fewer clouds form

↓

Reduced rainfall

↓

Droughts

 This is why deforestation can cause drought.

 How Can Deforestation Cause Both Droughts and Floods?

It may sound confusing, but both happen due to different effects.

 Causes of Drought

• Less trees → less transpiration
• Less clouds → less rainfall
• Leads to drought

 Causes of Floods

• Tree roots normally hold soil and absorb water.
• Without trees:
  • Water does not soak into soil (low infiltration)
  • Water flows quickly on the surface

 Flow Chart — Floods

Deforestation

↓

Soil becomes loose and hard

↓

Water not absorbed into ground

↓

More surface runoff

↓

Floods

So, deforestation can cause both droughts and floods.

3. Soil Erosion

Trees hold soil firmly with their roots.

 Flow Chart

Deforestation

↓

No roots to hold soil

↓

Top fertile soil washed away

↓

Soil erosion

 Result: Land becomes less fertile.

4. Desertification

When fertile soil keeps getting lost, the land slowly becomes desert-like.

 Flow Chart

Soil erosion

↓

Loss of humus and nutrients

↓

Soil becomes hard and dry

↓

Fertile land turns into desert

↓

Desertification

5. Lowering of Groundwater Level

• Trees help rainwater seep into the ground.
• Without trees → less water goes underground.

Result:

• Groundwater level falls
• Wells and hand pumps may dry up

6.Loss of Forest Products

 We get many products from forests:

• Timber (wood)
• Paper
• Fruits and nuts
• Honey
• Gum and resins
• Medicines
• Rubber
• Fuel wood

 Yes, if we keep cutting trees, we will face shortage of these products.

 How Animal Life is Affected

Deforestation badly affects animals.

Points to remember:

• Animals lose their homes (habitat loss)
•  Shortage of food for herbivores
•  Animals forced to move to human areas
•  Increase in human–animal conflicts
•  Many species become endangered or extinct
•  Food chains get disturbed
•  Biodiversity decreases

  Revision

• Deforestation → more CO₂ → global warming
• Disturbs water cycle → less rainfall
• Causes soil erosion and desertification
• Lowers groundwater level
• Leads to floods and droughts
• Harms animal life and biodiversity
• Causes shortage of forest products