Biogeochemical Cycles
Biogeochemical Cycles
Carbon Cycle
The carbon cycle involves the constant movement of carbon atoms between the atmosphere and Earth. In this closed system, the total amount of carbon remains unchanged, while its location shifts among various reservoirs.
Key Points:
Reservoirs of Carbon:
The majority of carbon on Earth is stored in rocks and sediments.
Other reservoirs include the oceans, atmosphere, and living organisms.
Processes that Release Carbon:
When organisms die, volcanic eruptions, wildfires, fossil fuel combustion, etc.
Carbon Exchange with Oceans:
Carbon is exchanged between the ocean surface and the atmosphere. Marine life turns carbon into organic matter using calcium carbonate, primarily for shells and skeletons.
Phosphorus Cycle
Phosphorus is essential for life, playing a key role in cell development and the production of ATP, DNA, and lipids in both plants and animals.
Key Points:
Chemical Properties:
Phosphorus occurs in compound forms and is mostly found in rock formations and ocean sediments as phosphate salts.
Phosphorus Releases:
Phosphorus is released from rocks through weathering, forming phosphates that may enter water bodies.
Plant Growth Limitation:
The limited quantities of phosphorus in soil often restrict plant growth, which is why phosphate fertilizers are commonly applied. Animals obtain phosphates by consuming plants or herbivores.
Nitrogen Cycle
Nitrogen is the most abundant element in the atmosphere and is crucial for various life processes. It exists in different forms throughout the environment.
Key Points:
Significance:
Nitrogen is a key building block of DNA and essential for plant growth, thus necessary for the food supply.
Forms of Nitrogen:
In the atmosphere, nitrogen is primarily found as gas (N2), while it exists as nitrogen oxides (NO, NO2) and ammonia (NH3) in the soil, especially when used as fertilizer.
Nitrogen Fixation:
This is the process by which nitrogen changes forms to move into different cycles.
Eutrophication:
Excess nitrogen can lead to water pollution and algal blooms, reducing oxygen levels, creating dead zones where aquatic life cannot survive.
Hydrologic (Water) Cycle
The hydrologic cycle involves the continuous circulation of water within the Earth-Atmosphere system, fundamentally moving water from the ground to the atmosphere and back.
Key Processes:
Evaporation:
The transition from liquid water to gas.
Transpiration:
The evaporation of water from plants.
Condensation:
Water vapor in the atmosphere condenses to form clouds (liquid state).
Precipitation:
Occurs when condensation results in droplets that are too large to remain airborne, falling to Earth as rain, snow, sleet, or hail.
Runoff:
Excessive precipitation results in water flowing over the ground into rivers and lakes.
Interaction of Biogeochemical Cycles
Each biogeochemical cycle operates independently for its constituent element (C, N, P), but they also interconnect through various chemical transformations.
Key Insights:
Faster decomposition of organic carbon enhances nitrogen availability for plants.
Plants can increase carbon uptake from the atmosphere, thereby improving ecological balance by reducing atmospheric CO2 levels.
Sources:
https://oceanservice.noaa.gov/facts/carbon-cycle.html
https://www.sciencelearn.org.nz/resources/961-the-phosphorus-cycle
https://www.youtube.com/watch?v=KNLUzqW8luA
https://www.youtube.com/watch?v=Wzo-uFS7LUA
https://www.youtube.com/watch?v=K5EOZenSSB8
https://kids.frontiersin.org/article/10.3389/frym.2019.00041
https://www.youtube.com/watch?v=FzYiPpxP-Cw
https://www.weather.gov/jetstream/hydro
https://www.esrl.noaa.gov/gmd/education/infoactivities/pdfs/TBIbiogeochemical_cycles.pdf
https://biologydictionary.net/biogeochemical-cycles-connect/
https://phys.org/news/2017-04-carbon-nitrogen-interact-vegetation-shifts.html
https://slideplayer.com/slide/15725007/