Phosphorus Cycle

• Define phosphorus and explain its importance for all living things.

• Describe the main steps of the phosphorus cycle.

• Analyze how human activities impact the phosphorus cycle and aquatic ecosystems.

Key Vocabulary

Weathering

The breakdown of rocks by wind and rain releases essential minerals like phosphate into the environment.

Decomposition

Decomposers like bacteria break down dead organic matter, returning nutrients back to the soil.

Eutrophication

The harmful overgrowth of algae and aquatic plants in water caused by excess nutrients like phosphorus.

Sedimentation

The process where phosphorus in water settles and accumulates at the bottom, forming layers of sediment.

Geological Uplift

The natural process that brings new rock, containing phosphate, from deep within the Earth to the surface.

What is Phosphorus?

• Phosphorus (P) is a chemical element and a vital nutrient for all life.

• ​It is a crucial component of DNA, RNA, and is vital for bone health.

• Phosphorus is a major nutrient that is essential for healthy plant growth.

• Its nutrient cycle occurs on land, with most phosphorus stored in rocks.

The Phosphorus Cycle

• Weathering and erosion of phosphate-rich rocks releases phosphate into the environment.

• Runoff and leaching transport phosphate ions into the soil and water.

• Plants absorb this phosphate, which is then transferred to animals that eat them.

• Decomposition of dead organisms returns phosphate back into the soil and water.

Long-Term Cycle

• Phosphorus in water settles out, forming layers of sediment on the bottom.

• Over geologic time, pressure transforms this sediment into new rock formations.

• This rock returns to the surface through geological uplift, completing a very slow cycle.

Human Impact

• Humans mine phosphorus-rich rocks to create commercial fertilizers for agricultural use.

• Runoff from farms introduces excess phosphorus into lakes, rivers, and oceans.

• This overload causes eutrophication, a process that depletes oxygen and harms aquatic life.

• Phosphorus is an essential nutrient for life, forming parts of DNA and RNA.

• The cycle begins with rock weathering, releasing phosphate into the soil and water.

• Plants absorb phosphate, which moves up the food chain and is returned by decomposition.

• Human activities can add excess phosphorus, causing damage to aquatic ecosystems.