UPSC CSE Prelims
Question 78
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?
- Burrowing animals and termites
- Fire
- Grazing herbivores
- Seasonal rainfall
- Soil properties
Select the correct answer using the code given below.
View correct answer and explanation
Correct answer: C
Correct Option: C (2, 3 and 4)
Explanation: Savannah woodland density is limited by recurrent fires, grazing and strongly seasonal rainfall. Other soil or animal effects matter locally, but the exam’s core broad drivers are items 2, 3 and 4.
Statement / Pair / Item-wise Analysis:
1. Incorrect / does not qualify - Burrowing animals/termites can affect soils locally but are not selected as the principal broad controls here.
2. Correct / qualifies - Frequent fires suppress tree seedlings and favour grasses.
3. Correct / qualifies - Grazers and browsers can prevent woody regeneration.
4. Correct / qualifies - A long dry season restricts continuous tree growth.
5. Incorrect / does not qualify - Soils influence tree cover but are not included in the asked principal set.
Option-wise Analysis:
A. Incorrect-includes item 1, which is not valid (Burrowing animals/termites can affect soils locally but are not selected as the principal broad controls here); omits valid item 3 (Grazers and browsers can prevent woody regeneration); omits valid item 4 (A long dry season restricts continuous tree growth).
B. Incorrect-includes item 5, which is not valid (Soils influence tree cover but are not included in the asked principal set); omits valid item 2 (Frequent fires suppress tree seedlings and favour grasses); omits valid item 3 (Grazers and browsers can prevent woody regeneration).
C. Correct-selects exactly the supported statements/items: 2, 3, 4.
D. Incorrect-includes item 1, which is not valid (Burrowing animals/termites can affect soils locally but are not selected as the principal broad controls here); includes item 5, which is not valid (Soils influence tree cover but are not included in the asked principal set); omits valid item 2 (Frequent fires suppress tree seedlings and favour grasses); omits valid item 4 (A long dry season restricts continuous tree growth).
Review note: Ecologically, soil conditions and termites can also affect savannah tree cover; this item has a narrow exam-key interpretation.