Environment and Ecology
2022
Ecology & Ecosystems

"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?

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

Correct Answer: Option D

The analogy compares rainforests to lungs (gas exchange) and wetlands to kidneys (filtration).

Wetlands act as "Earth's kidneys" due to their ability to filter pollutants from water.

Aquatic plants in wetlands absorb heavy metals and excess nutrients, effectively cleansing the water, similar to how kidneys filter blood.

Options A, B, and C describe other important functions of wetlands, but they don't directly relate to the filtration analogy.

Hence, option D is the most appropriate answer.