PHOSPHORUS CYCLE
Although nitrogen and carbon exist as gases, other elements collect in rocks and soil and are not found as a gas – such as Phosphorus. Phosphorus is important to life because it is found in DNA (your genetic information) and ATP (which is what all living things get energy from!). Without Phosphorus life would not be possible! Today we will be following the steps of the Phosphorus cycle.
The main phosphorus reservoir (place where phosphorus collects) is rock and soil so this is where the cycle begins – in the picture the main reservoir is the volcano.
Erosion occurs as water runs over rock, washing the phosphorus into rivers and streams.
Then, phosphorus mixes with oxygen to form phosphate and enters a major body of water, depicted here as a lake.
Next, the water containing phosphate is absorbed (taken in) by the plants and are used to make DNA & ATP.
In order for animals to get the phosphate they need, they must consume (eat) plants.
When plants and animals release waste or die, the phosphate in their bodies decompose and the phosphate is returned to the soil or water – at this point it can be reabsorbed by plants once again!
Large amounts of phosphate is carried by rivers and streams as runoff to the ocean.
This phosphate then concentrated (settles) in marine sediment - creating "ocean rocks". Just like on land, aquatic plants then absorb the Phosphorus and the animals eat the plants to get the Phosphorus they need.
As we have seen, the atmosphere is not involved in the phosphorus cycle because it is not found in a gaseous form. This is very different from the carbon and water cycle were the atmosphere is a main part of each cycle.