The primary source of phosphorus in ecosystems comes from the weathering of rocks and minerals containing phosphate. Phosphorus is a vital nutrient for living organisms, as it is an essential component of nucleic acids, ATP, and cell membranes. In terrestrial ecosystems, phosphorus often becomes available through soil amendments, animal waste, and organic matter decomposition. In aquatic systems, phosphorus can enter through runoff, influencing primary production and limiting factors for algal blooms and other aquatic plants, underscoring its importance in ecological balance.