Nutrient Cycle in a Forest Ecosystem

- The diagram illustrates the nitrogen cycle, showing how nitrogen moves through the atmosphere, soil, and living organisms.
- Nitrogen gas (N₂) from the atmosphere is converted into ammonia (NH₃) by nitrogen-fixing bacteria in the soil or root nodules of legumes.
- Ammonia is then converted into nitrites (NO₂⁻) and nitrates (NO₃⁻) by nitrifying bacteria, making it available for plant uptake.
- Plants incorporate nitrogen into proteins and nucleic acids; animals obtain nitrogen by consuming plants or other animals.
- When organisms die or excrete waste, decomposers break down organic matter, releasing ammonia back into the soil (ammonification).
- Denitrifying bacteria convert nitrates back into nitrogen gas, which returns to the atmosphere, completing the cycle.
- Human activities such as fertilizer use and fossil fuel combustion can disrupt the natural balance of the nitrogen cycle.