Biogeochemical cycles

Biogeochemical cycles

1. Water cycle

   • sublimination
     • ice directly converts into water vapors
   • transpiration
     • liquid water is turned into water vapor by the plants by using photosynthesis
   • runoff
     • the water pours down (in whatever form), water runs over the surface of earth.
   • other
     • evaporation
     • condensation
     • precipitation
   • infiltration
     • water that precipitates that doesn't runoff is absorbed by the plants
   • definition
     • path that all water follows as it moves around Earth in different states

2. Carbon cycle

   • carbon → atmosphere → plants
     • carbon is attached to oxygen by CO2 → through photosynthesis, CO2 → food for plant growth.
   • carbon → plants → animals
     • carbon in plants → animals that eat them
   • carbon → plants and animals → soils
     • dead plants and animals → bring carbon into the ground → fossil fuels
   • carbon → living things → atmosphere
     • CO2 → atmosphere → animals and plants get rid of CO2 by respiration
   • carbon → fossil fuels → atmosphere when fuels are burned
   • carbon→ atmosphere → oceans
     • bodies of water absorb some carbon from the atmosphere
   • definition
     • carbon atoms travel from the atmosphere to the Earth and then back into the atmosphere.

3. Nitrogen cycle

   • definition
     • nitrogen is converted into multiple chemical forms as it circulates among atmosphere and ecosystems
   • nitrogen fixation
     • (N2 to NH3/ NH4+ or NO3-)
   • nitrification
     • (NH3 to NO3-)
   • assimilation
     • (Incorporation of NH3 and NO3- into biological tissues)
   • ammonification
     • (organic nitrogen compounds to NH3)
   • denitrification
     • (NO3- to N2)

4. Phosphorus cycle

   • definition
     • movement of phosphorus through the lithosphere, hydrosphere, and biosphere
   • weathering
     • phosphorus in rocks → phosphate salts broken down → salts washed away → mix in the soil
   • absorption by plants
     • phosphate salts dissolved in water → absorbed by the plants
     • aquatic plants absorb inorganic phosphorus → they affect plant growth in aquatic ecosystems
   • absorption by animals
     • animals absorb phosphorus from plants or by consuming plant-eating animals
   • return to the environment through decomposition
     • when the plants and animals die they are decomposed by microorganisms
     • soil and water → sediments and rocks → release phosphorus by weathering