UPSC Prelims 2002 Q17: Geography – Biogeography & Natural Vegetation
Open stunted forests with bushes and small trees having long roots and sharp thorns or
spines are commonly found in
- (a) Eastern Orissa
- (b) North - eastern Tamil Nadu
- (c) Siwaliks in Terai region
- (d) Western Andhra Pradesh
Answer: (d) Western Andhra Pradesh
Explanation
Region of open stunted forests with thorny bushes
| Vegetation type | Features and region |
|---|---|
| Tropical thorn forest and scrub | Rainfall below 50-70 cm; stunted trees, long roots, thorns or spines |
| Where found | Rajasthan, Gujarat, Punjab-Haryana south-west, and western Andhra Pradesh (Rayalaseema), Karnataka plateau |
| Typical species | Acacia (babul), cactus, khair, euphorbias |
| Not found in | The wetter Eastern Odisha, north-east Tamil Nadu coast and Siwalik Terai belt |
These are tropical thorn forests, found in dry areas where rainfall is low. Of the options, the semi-arid western Andhra Pradesh (the rain-shadow interior) fits them. Eastern Odisha and the Terai have moist deciduous or other forests.
Answer: (d) Western Andhra Pradesh.
Why each option is right or wrong
- (a) Incorrect. Eastern Odisha gets heavy rain and has moist deciduous forests.
- (b) Incorrect. North-eastern Tamil Nadu has tropical dry evergreen forests on the coast.
- (c) Incorrect. The Siwalik-Terai belt has moist deciduous forests and tall grasslands.
- (d) CORRECT. Western Andhra Pradesh is dry and has thorn forests.
Key point
Thorn forests occur in areas with less than 70 cm rain: north-west India and the interior peninsula.
Remember
Thorn forest = low rain = Rajasthan, Gujarat and interior Andhra and Karnataka.
Common mistakes
- Choosing north-eastern Tamil Nadu because of its dry season.
- Linking Terai with thorny vegetation.
- Mixing tropical dry evergreen with thorn forest.
Exam tip
Thorny + stunted + long roots = dry rain-shadow region.
Sources
- NCERT Class XI — India: Physical Environment (Natural Vegetation)
- H. G. Champion and S. K. Seth — A Revised Survey of the Forest Types of India (Government of India, 1968)