The phosphorus cycle is the process by which phosphorus moves through the environment, primarily through soil, water, and living organisms. Unlike other nutrients, phosphorus does not have a gaseous phase and mainly exists in rocks and minerals. Weathering of these rocks releases phosphorus into the soil, where it can be absorbed by plants. When animals eat these plants, phosphorus enters their bodies. After they die, decomposition returns phosphorus to the soil, where it can be reused by plants. Additionally, phosphorus can run off into water bodies, contributing to aquatic ecosystems, but excessive amounts can lead to problems like algal blooms.