How does nitrogen cycle through an ecosystem?

When plants and animals die or when animals excrete wastes, the nitrogen compounds in the organic matter re-enter the soil where they are broken down by microorganisms, known as decomposers. This decomposition produces ammonia, which can then go through the nitrification process

the nitrogen compounds in the organic matter and re-enters the soil where they are broken down by microorganisms known as decomposers

d.

explanation:

layer 3 is younger than layer 6.