UPSC Prelims 2010 Q1: Geography – Biogeography & Natural Vegetation

UPSC Prelims 2010, General Studies Paper I · Geography

A geographic area with an altitude of 400 metres has following characteristics: Month J F M A M J J A S O N D Average maximum temp. °C 31 31 31 31 30 30 29 28 29 30 31 Average minimum temp. °C 21 21 21 21 21 20 20 20 20 20 20 Rainfall (mm) 51 85 188 158 139 121 134 168 185 221 198 86 If this geographic area were to have a natural forest, which one of the following would it most likely be?

(a) Moist temperate coniferous forest
(b) Montane subtropical forest
(c) Temperate forest
(d) Tropical rain forest

Answer: (d) Tropical rain forest

Explanation

Identifying the forest type from climate data

The area has an altitude of 400 m, maximum temperatures around 28-31°C year-round, minimum temperatures around 20-21°C, and heavy rainfall (51-221 mm monthly, no real dry season).

Option	Verdict	Reason
(a) Moist temperate coniferous forest	Incorrect	This forest type needs cooler, higher-altitude conditions, not consistently 28-31°C temperatures
(b) Montane subtropical forest	Incorrect	'Montane' implies higher altitude/cooler zones, inconsistent with 400m and consistently warm temperatures
(c) Temperate forest	Incorrect	Temperate forests need much cooler, seasonal temperature swings, not a uniform 28-31°C
(d) Tropical rain forest	Correct	Low altitude, uniformly high temperatures, and heavy, well-distributed rainfall year-round are the signature conditions for tropical rain forest

Reading climate data for forest type:

Clue	Points to
Low altitude (400m)	Rules out montane/temperate zones
Uniform high temp (28-31°C)	Rules out temperate/coniferous
Heavy, evenly spread rainfall	Tropical rain forest

Answer: (d) Tropical rain forest.

Why each option is right or wrong

(a) Incorrect. Moist temperate coniferous forest needs cooler, higher-altitude conditions, not this uniformly warm climate.
(b) Incorrect. Montane subtropical forest implies higher elevation and cooler conditions than this 400m, warm-climate profile.
(c) Incorrect. A temperate forest needs cooler, more seasonal temperatures, unlike the steady 28-31°C shown here.
(d) CORRECT. The low altitude, uniform high temperature, and heavy year-round rainfall are classic tropical rain forest conditions.

Key point

Low altitude + uniformly high temperatures (28-31°C) + heavy, well-distributed rainfall year-round = TROPICAL RAIN FOREST, not temperate/montane/coniferous types which need cooler or more seasonal climates.

Remember

Tropical rain forest: low altitude, uniformly high temperatures, heavy year-round rainfall — matches the Q1500 climate table.

Common mistakes

Assuming any forest at a non-zero altitude must be montane or temperate.
Missing that the rainfall is spread across all months, not seasonal, ruling out drier forest types.
Not connecting uniformly high temperatures specifically to tropical (not temperate) forest classification.

Exam tip

Low altitude + hot + wet all year = tropical rain forest. Watch for 'montane'/'temperate' as climate-mismatched distractors.

Sources

NCERT Class XI Geography — 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)

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