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

Learn more about the functions of wetlands in the given explanation below.

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”.

Importance of Wetland Ecosystem

Wetlands are important ecosystems that provide numerous beneficial services for people and for fish and wildlife. Some of these services, or functions, include:

  • Fish Harvest: Wetlands are highly productive ecosystems that provide the world with nearly two-thirds of its fish harvest.
  • Ecology of the Watershed: Wetlands play an integral role in the ecology of the watershed. The combination of shallow water, and high levels of nutrients is ideal for the development of organisms that form the base of the food web and feed many species of fish, amphibians, shellfish and insects.
  • Global Cycles: Wetlands’ microbes, plants and wildlife are part of global cycles for water, nitrogen and sulphur. Wetlands store carbon within their plant communities and soil instead of releasing it to the atmosphere as carbon dioxide.
  • Natural Barriers: Wetlands function as natural barriers that trap and slowly release surface water, rain, snowmelt, groundwater and flood waters. Wetland vegetation also slows the speed of flood waters lowering flood heights and reduces soil erosion.
  • Biodiversity: Wetlands are critical to human and planet life. More than one billion people depend on them for a living and 40% of the world’s species live and breed in wetlands. Wetlands provide habitat for animals and plants and many contain a wide diversity of life, supporting plants and animals that are found nowhere else.
  • Source of Resources: Wetlands are a vital source for food, raw materials, genetic resources for medicines, and hydropower.
  • Transport, Tourism and Culture: Wetlands play an important role in transport, tourism and the cultural and spiritual well-being of people. Many wetlands are areas of natural beauty and promote tourism and many are important to Aboriginal people.
  • Industry: Wetlands also provide important benefits for industry. For example, they form nurseries for fish and other freshwater and marine life and are critical to commercial and recreational fishing industries.

Therefore, option (4) is the correct answer.

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