The vegetation of savannah consists of grassland with scattered small trees, but extensive areas have no trees. The forest development in such areas is generally kept in check by one or more or a combination of some conditions. Which of the following are such conditions? 1. Burrowing animals and termites 2. Fire 3. Grazing herbivores 4. Seasonal rainfall 5. Soil properties Select the correct answer using the code given below.
- (a) 1 and 2
- (b) 4 and 5
- (c) 2, 3 and 4 ✓ UPSC's answer
- (d) 1, 3 and 5
Why the answer is (c)
• Savannas persist as grassland because tree establishment is repeatedly checked by disturbance and climate.
• Fire (2), often set in the dry season, kills tree seedlings while grasses resprout from their bases.
• Grazing and browsing herbivores (3) — elephants, giraffes, wildebeest — trample and eat saplings.
• Strongly seasonal rainfall (4) with a long dry season prevents the year-round moisture that closed forest needs.
• Burrowing animals and termites (1) and soil properties (5) shape local patterns but are not the main controls listed in the key.
• Hence 2, 3 and 4, option (c).
Why the other options are wrong
- (a) 1 and 2
- Grazing and seasonal rainfall are key controls; burrowers are not.
- (b) 4 and 5
- Fire and grazing are the main checks; soil alone is not.
- (d) 1, 3 and 5
- Fire and seasonal rainfall are the principal controls omitted here.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2021, held on 10 October 2021. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.