Why is the nitrogen cycle important for ecosystems?

The nitrogen cycle is vital for ecosystems primarily because it converts nitrogen, which is abundant in the atmosphere in its gaseous form, into usable forms that living organisms can assimilate, such as ammonia, nitrate, and nitrite. Most organisms, including plants, cannot directly utilize atmospheric nitrogen. Through the processes of nitrogen fixation, nitrification, and ammonification, nitrogen is transformed into forms that plants can absorb through their roots.

This process supports the synthesis of essential biomolecules like DNA, RNA, and proteins. Without the nitrogen cycle, ecosystems would face significant limitations in productivity, as plants would be unable to obtain the necessary nitrogen to grow and thrive, thereby affecting the entire food web. Thus, the health and sustainability of ecosystems largely depend on the effective functioning of the nitrogen cycle, making it crucial for biological diversity and productivity.