Carbon Cycling (4.3) Flashcards
Carbon is released into the atmosphere by:
- Respiration (in particular by decomposers)- Methane production- Combustion of fossil fuels and biomass- Limestone decomposition- Diffusion
Carbon Release: Respiration
Carbon dioxide is produced through respiration and diffuses out of organisms into water or the atmosphere. In particular respiration by decomposers eg. saprophytic bacteria and fungi.
Carbon Release: Methane
Methane CH₄ is produced under anaerobic conditions by methanogenic archaeans. Some diffuses into the atmosphere and accumulates in the ground. Methane is also produced in the gut of grass feeding animals eg. livestock and oxidizes to carbon dioxide and water in the atmosphere.
Carbon Release: Combustion
The combustion of fossil fuels produces carbon dioxide and water. The combustion of biomass i.e. the burning of trees, produces carbon dioxide, methane and other harmful greenhouse gases.
Carbon Release: Limestone Decomposition
Limestone (CaCO₃) decomposition caused by acidic environments or heat.
Carbon is removed from the atmosphere by:
- Autotrophs (photosynthesis)| - Diffusion
Carbon Removal: Autotrophs
Autotrophs (eg. plants and phytoplankton) convert carbon dioxide into carbohydrates and other carbon compounds through photosynthesis.
Carbon Removal: Diffusion
Carbon dioxide diffuses from the atmosphere and/or ocean (bodies of water) to autotrophs.
Carbon is stored as/in:
- Fossil Fuels- Limestone- Biomass- In Aquatic Ecosystems- Peat
Carbon Storage: Fossil Fuels
Carbon is stored in fossil fuels. Fossil fuels are partially decomposed organic matter (mainly plants) from past geological eras that has converted into coal and oil/gas accumulating in porous rock. This process is called carbonification
Carbon Storage: Limestone
Organisms like coral and Mollusca have bones or shells made of calcium carbonate so can become fossilised in limestone.
Carbon Storage: Biomass
Biomass of living things (eg. plants, animals and plankton) have organic compounds containing carbon such as carbohydrates, proteins, fats, calcium carbonate bones and shells and chitin exoskeletons.
Carbon Storage: Aquatic Ecosystems
In aquatic ecosystems (eg. oceans and lakes) carbon is present as dissolved carbon dioxide and hydrogen carbonate ions.
Carbon Storage: Peat
Peat is formed under wet, acidic and anaerobic conditions from organic matter that has not been fully decomposed by saprotrophs. Peat usually forms as thick deposits in boggy swamps.