Elemental phosphorus mainly exists in nucleotides and cell membranes in organisms. At the same time, phosphoric acid also plays an important role in biological material metabolism and energy metabolism. Therefore, phosphorus is an essential element for all biological cells.
① (phosphate)dissolved in the biosphere in the form of phosphate solution;
② (phosphate)insoluble in the biosphere in the form of phosphate molecules. Phosphorus cycling is mainly between soil, plants and microorganisms. Microorganisms play an important role in it. They not only participate in the dissolution of inorganic phosphates and the mineralization of organic phosphates, but also participate in the assimilation of soluble phosphorus. The phosphorus cycle is also affected by temperature, pH and other environmental conditions. For example, the concentration of inorganic phosphorus in water often fluctuates with seasons. The water temperature gradually decreases in autumn. After the death of algae, it is decomposed by heterotrophic microorganisms, and the concentration of inorganic phosphorus increases. The released inorganic phosphorus will be assimilated by bacteria and algae when the temperature gets warmer and the water temperature is appropriate in the next year, so that the concentration of inorganic phosphorus decreases.