Essential idea: Continued availability of carbon in ecosystems depends on carbon cycling
Nature of science:
Making accurate, quantitative measurements—it is important to obtain reliable data on the concentration of carbon dioxide and methane in th
- Autotrophs convert carbon dioxide into carbohydrates and other carbon compounds.
- In aquatic ecosystems carbon is present as dissolved carbon dioxide and hydrogen carbonate ions.
- Carbon dioxide diffuses from the atmosphere or water into autotrophs.
- Carbon dioxide is produced by respiration and diffuses out of organisms into water or the atmosphere.
- Methane is produced from organic matter in anaerobic conditions by methanogenic archaeans and some diffuses into the atmosphere or accumulates in the ground.
- Methane is oxidized to carbon dioxide and water in the atmosphere.
- Peat forms when organic matter is not fully decomposed because of acidic and/or anaerobic conditions in waterlogged soils.
- Partially decomposed organic matter from past geological eras was converted either into coal or into oil and gas that accumulate in porous rocks.
- Carbon dioxide is produced by the combustion of biomass and fossilized organic matter.
- Animals such as reef-building corals and mollusca have hard parts that are composed of calcium carbonate and can become fossilized in limestone
Applications and skills:
- Application: Estimation of carbon fluxes due to processes in the carbon cycle.
- Application: Analysis of data from air monitoring stations to explain annual fluctuations.
- Skill: Construct a diagram of the carbon cycle.
- Carbon fluxes should be measured in gigatonnes.