Biogeochemical Cycles

The Water Cycle

  • Evaporation

    • Energy from the sun causes water to evaporate from the Earth’s surface

    • Liquid - Gaseous State

    • 600 calories of energy is absorbed for each gram of water

  • Condensation

    • Condensation is the process by which water vapor changes it's physical state from a vapor, most commonly, to a liquid.

    • It condenses into droplets around dust particles in the atmosphere

  • Precipitation

    • Precipitated water may fall into a waterbody or it may fall onto land. It is then dispersed several ways. The water can adhere to objects on or near the planet surface or it can be carried over and through the land into stream channels, or it may penetrate into the soil, or it may be intercepted by plants.

    • It precipitates to earth’s ground in the form of rain or snow.

  • Percolation

    • Water percolates, or moves through the soil and enters groudwater

  • Transpiration

    • Water inside of plants is transferred from the plant to the atmosphere as water vapor through numerous individual leave openings. Plants transpire to move nutrients to the upper portion of the plants and to cool the leaves exposed to the sun.

  • Runoff

    • Runoff is flow from a drainage basin or watershed that appears in surface streams. It generally consists of the flow that is unaffected by artificial diversions, storages or other works that society might have on or in a stream channel

The Carbon Cycle

  1. Photosynthesis: Plants absorb carbon dioxide (CO2) from the atmosphere during photosynthesis, converting it into organic carbon compounds.

  2. Consumption: Animals consume plants and other organisms, incorporating carbon into their tissues through the food chain.

  3. Respiration: Organisms release carbon dioxide (CO2) back into the atmosphere through respiration, breaking down organic compounds to release energy.

  4. Decomposition: Decomposers break down dead organic matter, releasing carbon dioxide (CO2) and methane (CH4) into the atmosphere or soil.

  5. Combustion: Human activities, such as burning fossil fuels and deforestation, release additional carbon dioxide (CO2) into the atmosphere, contributing to climate change.

Carbon and oxygen remain in deposits until weathering and erosion release them from rocks

These steps illustrate how carbon cycles through the biosphere, atmosphere, hydrosphere, and lithosphere, influencing Earth's climate and ecosystems.

Largest reservoir: Deep ocean

The Nitrogen Cycle

  1. Nitrogen Fixation

    • Atmosphere:

      • Two atoms of nitrogen gas react to oxygen and separate through lightning is called nitrogen fixation in the atmosphere

      • The nitrogen fixed into nitrates by the lighting will reach the ground through rain

    • Soil:

      • Bacteria in the roots of beans and legumes converts nitrogen gas into ammonium

      • This ammonium is absorbed by the roots of plants

  2. Nitrification

    • The large amount of nitrogen fixation is accomplished by nitrifying bacteria.

    • They convert ammonium into nitrate to be absorbed by the roots of plants

    • Process of converting ammonia to nitrate

  3. Assimilation

    • The nitrates are absorbed by the roots of plants in the soil.

    • Without sufficent nitrate, the plants will not grow will and the leaves will turn yellow

  4. Ammonification

    • Plants and animals that consume nitrogen will be dead overtime and decay

    • The decompsers= fungi and bacteria will convert it to ammonia through the process

      • Some ammonia will be aborbed by the tree

      • some will go through nitrifcation

  5. Denitrification

    • Returning nitrogen back to the atmosphere

    • The nitrogen produced from nitrogen fixation will be converted again into nitrogen gas by denytrifying bacteria

Human contribution: Human activites affect the nitrogen cycle as the runoff from fertilizer can create algae overgrowth and nitrogen oxygen compounds are released into the atmosphere from factors combine with water.

The Phosphorus Cycle

  1. Weathering

    • Environmental, Biological, Chemical Weathering where phosphorus is transferred from the rocks to the ground

    • it’s contained in sedimentary and igenous rocks initially

    • Phosphorus moves in a cycle through rocks, water, soil and sediments and organisms. Over time, rain and weathering cause rocks to release phosphate ions and other minerals. This inorganic phosphate is then distributed in soils and water. Plants take up inorganic phosphate from the soil.