Biogeochemical Cycles (carbon, nitrogen and phosphorus)

Biogeochemical Cycles (carbon, nitrogen and phosphorus)

1. Key Concepts Introduction to Biogeochemical Cycles Biogeochemical cycles refer to the natural processes that recycle elements essential for life, such as carbon, nitrogen, oxygen, phosphorus, and water, throughout the biosphere. These cycles involve the transformation and movement of these elements between different reservoirs, including the atmosphere, lithosphere, hydrosphere, and biosphere.

2. Types of Biogeochemical Cycles The Carbon Cycle

3. Main Processes Photosynthesis: Plants absorb atmospheric CO₂ to produce glucose, storing carbon in biomass. Respiration: Organisms release CO₂ back into the atmosphere by breaking down organic molecules for energy. Decomposition: Decomposers break down dead organisms, releasing carbon into the soil and atmosphere. Fossilization: Over long periods, organic matter can form fossil fuels, storing carbon in the lithosphere. Combustion: Burning fossil fuels releases stored carbon rapidly into the atmosphere as CO₂. Types of Biogeochemical Cycles The Carbon Cycle

4. Importance Nitrogen is essential for amino acids, proteins, and nucleic acids, making it critical for life. Atmospheric nitrogen (N₂) is abundant but mostly unavailable directly to living organisms. The Nitrogen Cycle

5. Main Processes The Nitrogen Cycle

6. The Phosphorus Cycle Importance Phosphorus is critical for DNA, RNA, ATP, and phospholipids, and hence is vital for energy transfer and cell structure. Unlike other cycles, phosphorus does not include a gaseous phase under typical Earth conditions.

7. The Phosphorus Cycle

8. The Water (Hydrological) Cycle Importance Water is essential for all life processes, acting as a solvent, medium, and reactant in biological and chemical processes. The water cycle regulates climate, weather patterns, and the distribution of nutrients.

9. The Water (Hydrological) Cycle

10. Human Impacts on Biogeochemical Cycles

11. Importance of Biogeochemical Cycles for Ecosystem Stability