The living components on Earth can survive because all the chemical elements which make up living cells is recycled continuously. This recycling is done through our biogeochemical cycles. We have the gaseous cycles which include nitrogen, oxygen, carbon, and water; and sedimentary cycles which include iron, calcium, phosphorus, sulfur, and other earthbound elements.
These elements within biogeochemical cycles flow from biotic components to abiotic components and then back. The abiotic portion of a cycle is generally slower than the biotic portion. For example, phosphorus in rocks is very slow to be released because weathering of rocks can take a long time. But once the phosphorus is available it is used by a plant such as a blueberry bush for growth. The blueberries from the bush can be then eaten by a black bear. The black bear will do what bears do in the woods and the phosphorus which is not used by the bear for cellular processes can be passed back to the soil.
And the biogeochemical cycles do not act independently of one another. Nutrients such as phosphorus and nitrogen are released by erosion of rocks and decomposition of organic matter in a river and then flow downstream thanks to the water cycle. These nutrients can support the growth of aquatic plants which provide oxygen and food for aquatic organisms.
The next time you sit down to eat dinner think about where your food came from and the different biogeochemical cycles which made this meal possible.