Question

UPSC Prelims 2022 Question:

“If rainforests and tropical forests are the lungs of the Earth, then surely wetlands function as its kidneys.” Which one of the following functions of wetlands best reflects the above statement?

  1. 1. The water cycle in wetlands involves surface runoff, subsoil percolation and evaporation.
  2. 2. Algae form the nutrient base upon which fish, crustaceans, molluscs, birds, reptiles and mammals thrive.
  3. 3. Wetlands play a vital role in maintaining sedimentation balance and Soil stabilization.
  4. 4. Aquatic plants absorb heavy metals and excess nutrients.

Answer (Detailed Solution Below)

Option 4: Aquatic plants absorb heavy metals and excess nutrients.

Detailed Solution

Explanation: 

  • According to The Ramsar Convention, “wetlands are areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres.”

  • Wetlands are vital for humans, for other ecosystems and for our climate, providing essential ecosystem services such as water regulation, including flood control and water purification. Wetlands also absorb carbon dioxide so help slow global heating and reduce pollution, hence have often been referred to as the “Kidneys of the Earth”.

Therefore, option (4) is the correct answer.

Subject: Environment|Biodiversity and Conservation

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