Three Cycles

water - carbon - nitrogen

Water cycle

The cycle begins with a body of water, most often being the ocean, that evaporates and condenses into clouds. After the clouds become heavy with water molecules, precipitation of water, snow, or hail comes down.

Carbon cycle

The carbon cycle, however, can occur upon different triggers. Though, we will only cover one. Dead organisms and animal waste break down into mineral carbon (or "Fossil Fuels"), which buries itself beneath the soil. Upon being burnt, gaseous carbon dioxide is released into the atmosphere.

Nitrogen cycle

A type of bacteria called nitrogen fixing bacteria take in atmospheric nitrogen and produce ammonia (NH3). Other bacteria use this ammonia to produce nitrates and nitrites. These are used by plants to make amino acids which are then used to make plant proteins. Plants are consumed by other organisms which use the plant amino acids to make their own.

Decomposers convert the nitrogen found in other organisms into ammonia and return it to the soil. A few of these type of bacteria return nitrogen to the atmosphere by a process called denitrification, however this amount is little.

Nitrogen is one of the primary nutrients critical for the survival of all living organisms. Although nitrogen is very abundant in the atmosphere, it is largely inaccessible in this form to most organisms. This article explores how nitrogen becomes available to organisms and what changes in nitrogen levels as a result of human activity means to local and global ecosystems.