UPSC Prelims 2011 Q76: Environment & Ecology – Water & Wetland Conservation
- (a) The mangrove swamps separate the human settlements from the sea by a wide zone in which people neither live nor venture out
- (b) The mangroves provide both food and medicines which people are in need of after any natural disaster
- (c) The mangrove trees are tall with dense canopies and serve as an excellent shelter during a cyclone or tsunami
- (d) The mangrove trees do not get uprooted by storms and tides because of their extensive roots
Answer: (d) The mangrove trees do not get uprooted by storms and tides because of their extensive roots
Explanation
How mangroves act as a safety hedge against coastal disasters
The 2004 Indian Ocean Tsunami highlighted mangroves' protective role for coastal communities.
| Option | Verdict | Reason |
|---|---|---|
| (a) Mangrove swamps separate settlements from the sea by a wide buffer | Incorrect | Mangroves don't work primarily by creating an uninhabited buffer zone; their protection comes from their physical structure |
| (b) Provide food/medicine after a natural disaster | Incorrect | This is a secondary benefit, not the mechanism explaining their role as a storm/tsunami 'safety hedge' |
| (c) Tall trees with dense canopies shelter during cyclone/tsunami | Incorrect | Mangroves are not valued for canopy shelter; their key protective feature is below the surface |
| (d) Extensive roots prevent uprooting by storms/tides | Correct | Mangroves' dense, extensive root systems anchor them firmly, letting them absorb and dissipate wave energy without being swept away, acting as a natural wave-breaking barrier |
Mangroves as coastal protection:
| Point | Detail |
|---|---|
| Key feature | Extensive root systems |
| Mechanism | Roots resist uprooting, dissipate wave energy |
| 2004 Tsunami lesson | Mangrove-protected coasts saw less damage than denuded ones |
Answer: (d) The mangrove trees do not get uprooted by storms and tides because of their extensive roots.
Why each option is right or wrong
- (a) Incorrect. The protective mechanism is structural (roots), not simply an uninhabited buffer zone.
- (b) Incorrect. Providing food/medicine is a secondary, post-disaster benefit, not the hedge mechanism itself.
- (c) Incorrect. Mangroves' protective value lies in their roots, not canopy shelter.
- (d) CORRECT. Their extensive root systems resist uprooting and dissipate wave energy, making them an effective natural barrier.
Key point
Mangroves serve as a coastal safety hedge because their extensive root systems resist uprooting by storms/tides and dissipate wave energy — not because of canopy shelter or buffer-zone distance alone.
Remember
Mangroves protect coasts via extensive root systems that resist uprooting and dissipate wave energy from storms/tsunamis.
Common mistakes
- Attributing mangrove protection to canopy cover rather than their root structure.
- Treating food/medicine provision as the core protective mechanism, when it's a secondary benefit.
- Missing the specific wave-energy dissipation function of mangrove root systems.
Exam tip
Mangrove protection = roots, not canopy. Their anchoring, wave-dissipating root systems are the key mechanism.
Sources
- Encyclopaedia Britannica — mangrove
- Food and Agriculture Organization of the United Nations — The World's Mangroves 1980–2005 (FAO Forestry Paper 153, 2007)