Question

14. What is the ecological importance of processes such as ammonification and nitrogen fixation? 15. When is denitrification useful for the environment, and when is it detrimental? 16. What is eutrophication and why does it happen? List some of its consequences.

Answer 1

Answer:

14. What is the ecological importance of processes such as ammonification and nitrogen fixation?

• Ammonification process involves the conversion of organic Nitrogen into inorganic ammonia (NH3) and it plays an important role in the Nitrogen cycle. Ammonification is carried by variety of microorganisms, and the free nitrogen released in this process is retained in soil and water. Ammonification provides living organisms Nitrogen which is an essential element. If ammonification doesn’t occur, then it will lead to accumulation of organic form of nitrogen in large quantities. However, for plants inorganic nitrogen is essential for growth instead of organic nitrogen. Therefore, ammonification is an important part of nitrogen cycle and plays an important role in maintaining the productivity of the ecosystem.
• Nitrogen fixation is the process of conversion of molecular Nitrogen into fixed form of nitrogen such as Ammonium (NH₄⁺) and nitrate (NO₃^–) which can be absorbed by plants. Nitrogen fixation is important because plants and animals cannot use the molecular form of Nitrogen (N₂) directly from the environment. Through nitrogen fixation, Nitrogen is converted into form that can be readily used by plants for growth and development.

15. When is denitrification useful for the environment, and when is it detrimental?

• Denitrification is the process of removal of nitrogen from ecosystem and its conversion back to the atmospheric Nitrogen (N₂).
• Denitrification is useful for the environment because it prevents the accumulation of organic form of Nitrogen in the soil and water. In the absence of denitrification these compounds can accumulate to toxic levels that are harmful for the growth of plants.
• Denitrification process can be detrimental since it results in depletion of soil fertility and reduction of agricultural productivity.

16. What is eutrophication and why does it happen? List some of its consequences.

• Eutrophication is the process whereby waterbodies becomes enriched with nutrients leading to an excessive increase of phytoplankton population (bloom).
• Eutrophication can occur due to several reasons such as:
  • Discharge of untreated sewage containing high levels of nitrates and phosphates
  • Runoff of fertilizers and nutrients from cultivation sites or agricultural land into the water bodies
  • Combustion of fossil fuels also results in deposition of nitrogenous compounds which subsequently are washed into water bodies.
• Consequences of Eutrophication:
  • Significant increase of algae and phytoplankton in water bodies.
  • Reduction in transparency of water (increase in turbidity).
  • Reduction in diversity of aquatic life
  • Depletion of dissolved oxygen levels in water bodies.