Assertion (A) >: Unlike temperate forests, the tropical rain forests, if cleared, can yield productive farm-land that can support intensive agriculture for several years even without chemical fertilizers. Reason (R) >: The primary productivity of the trop

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Q: 110 (IAS/2003)

Assertion (A): Unlike temperate forests, the tropical rain forests, if cleared, can yield productive farm-land that can support intensive agriculture for several years even without chemical fertilizers.
Reason (R): The primary productivity of the tropical rain forest is very high when compared to that of the temperature forests.

question_subject: 

Geography

question_exam: 

IAS

stats: 

0,60,90,65,17,8,60

keywords: 

{'tropical rain forests': [0, 0, 2, 1], 'temperate forests': [0, 0, 0, 1], 'tropical rain forest': [1, 0, 0, 2], 'temperature forests': [0, 0, 1, 0], 'intensive agriculture': [0, 0, 2, 0], 'productive farm': [0, 0, 1, 0], 'primary productivity': [0, 0, 2, 0], 'chemical fertilizers': [1, 0, 0, 1]}

The correct answer is option 4, which means that the Assertion (A) is false and the Reason (R) is true.

The Assertion (A) statement is incorrect because when tropical rain forests are cleared, the land does not remain productive for several years without chemical fertilizers. Tropical soils are generally poor in nutrients and when a rainforest is cleared, essential nutrients stored in the vegetation are lost quickly due to heavy rains and the soil is exhausted within a few years.

On the other hand, the Reason (R) statement is accurate as the primary productivity, which is the rate at which plants and other photosynthetic organisms produce organic compounds in an ecosystem, is indeed very high in tropical rainforests compared to temperate forests. This is because tropical rainforests have a longer growing season and a higher level of sunlight, both of which enhance photosynthesis and result in higher primary productivity.

Hence, while both statements are about tropical rainforests, the Reason (R) does not provide a correct explanation for the Assertion (A), making option 4 the accurate choice.