Science · Class 7
Forests: Our Lifeline
Food chain, forest products, and interdependence in ecosystems.
4 sections15–25 min read6 MCQs · 2 examples
Chapter Overview
Forests are complex ecosystems with producers, consumers, and decomposers. This chapter covers forest structure, interdependence, products, and why forests are called biodiversity hotspots.
Forest Structure
- Canopy: top layer of crowns
- Understorey, shrubs, forest floor
- Decomposers recycle nutrients on floor
Interdependence
- Herbivores, carnivores, omnivores linked in food chains
- Trees give shelter, food, oxygen; animals disperse seeds
- Deforestation disrupts entire web
Forest Products and Conservation
- Timber, fruits, medicines, rubber, resin
- Chipko movement — community forest protection
- Protected areas: national parks, sanctuaries
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
Food chain
Grass → deer → tiger. What if deer decrease?
- 1Tigers starve or migrate
- 2Grass may overgrow initially
- 3Balance of ecosystem disturbed
Answer
Tiger population declines; ecosystem imbalanced
Decomposers
Why are decomposers essential in forest?
- 1Break dead matter to humus
- 2Return nutrients to soil
- 3Without them nutrients locked in dead bodies
Answer
Nutrient cycling depends on decomposers
Key Points to Remember
- ✓ One tree supports many life forms
- ✓ Forest cover declining in some regions
- ✓ Afforestation restores green cover
Exam Tips
- • Draw forest food web
- • Explain canopy and understorey
- • Why is Chipko movement significant?
Practice MCQs — Forests: Our Lifeline
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Question 1 of 6Score: 0/0
Forest floor has: