Why is the circulation of substances considered the main condition for the existence of a natural community?

There are a large number of species of living organisms on Earth, the obligatory components of which are organic and inorganic substances. In addition, inorganic ones are part of inanimate nature. If we assume that at the death of any organism these elements do not return, then in a fast time they simply ended. This led to the gradual disappearance of such a great variety, because each element in a certain percentage provides normal vital activity.