The Nitrogen Cycle - Jenn Fitzgerald | Library

The atmosphere is made up of about 78% nitrogen gas (N2). Nitrogen is important to ecosystems because it limits the growth of organisms. Lightning is one of the many ways nitrogen can enter the cycle. 
Nitrogen is found in proteins. The largest concentration of nitrogen is found in the atmosphere. But plants and animals cannot use nitrogen directly from the atmosphere. The nitrogen must first undergo nitrogen fixation before plants can use it. 
Nitrogen is returned to the soil in several ways. When an animal urinates, nitrogen returns to the water or soil and can be reused by plants. When an organism dies, decomposers transform the nitrogen in proteins and other compounds back into ammonium. Organisms in the soil convert ammonium into nitrogen-oxygen compounds that can be used by plants called nitrification. 
Finally, a process called denitrification is done by other soil bacteria and converts nitrogen-oxygen compounds back into nitrogen gas, which returns to the atmosphere. 

Nitrogen Cycle: Terrestrial Community

Nitrogen Cycle: Aquatic Community

Nitrogen Cycle: Human Community 

Nitrogen Cycle: The Complete Cycle

Living organisms all depend on nitrogen to survive. Biological communities impact the nitrogen cycle in different ways.
The complete nitrogen cycle takes place not only across various environments, but throughout the entire biosphere. Organisms and abiotic factors across the globe are responsible for the cycling of matter.

1

Name 2 ways in which human activities impact the nitrogen cycle.

1

Identify how nitrogen cycles through subterranean environments.

1

Why is lightning an important factor in the nitrogen cycle?

5

In the nitrogen cycle, nitrogen is continuously recycled. Which type of organisms break down compounds in dead organisms and recycle them into the soil?