Biogeochemical Cycles
Principles of Biogeochemical Cycles
- Biogeochemical cycles represent the circular pathways by which elements move through earth’s air, water, soil, rock and living organisms.
- Cycles include the water cycle, carbon cycle, nitrogen cycle, phosphorus cycle, and sulphur cycle.
- Each cycle helps make essential nutrients available for organisms, supporting life on Earth.
- These cyclic pathways help maintain balance within ecosystems and regulate atmospheric gases associated with climate.
Water Cycle
- This cycle is a series of processes by which water circulates between the Earth’s oceans, atmosphere, and land.
- The key processes are evaporation, transpiration, condensation, precipitation, runoff, and infiltration.
- It helps distribute heat around the globe, contributing to Earth’s climate system.
Carbon Cycle
- The carbon cycle moves carbon, a necessary component of life and crucial greenhouse gas, through the biosphere.
- Key processes include photosynthesis, respiration, combustion (burning), and decay of organic matter.
- This cycle helps regulate Earth’s temperature by controlling the amount of carbon dioxide in the atmosphere.
Nitrogen Cycle
- Nitrogen is necessary for life as it is a component of amino acids and nucleic acids.
- The nitrogen cycle includes atmospheric nitrogen fixation by bacteria and lightning, synthesis of organic compounds, decay and nitrification, denitrification back to atmospheric nitrogen.
- This cycle helps maintain soil fertility and is essential for plant growth and development.
Phosphorus Cycle
- Unlike other cycles, the phosphorus cycle doesn’t have a significant atmospheric component; it circulates between water, soil, and organisms.
- Essential for ATP and DNA, processes include weathering of rocks, absorption by plants, consumption by animals, and return to soil via waste or decomposition.
- It plays a critical role in cell function and energy transfer.
Sulphur Cycle
- Sulphur cycles between the Earth’s atmosphere, living organisms, and the oceans.
- Includes processes like evaporation from water surfaces, released by volcanoes, decomposition of organic matter, and absorption by plants.
- Sulphur is crucial for protein synthesis and is a component of certain amino acids and vitamins.