Carbon cycle

• Why is nutrient cycling important

  Nutrients cycling is important because it allows nutrients to be released from tissues so that they become available again for other organisms to use. Without nutrient cycling ecosystems would run out of essential nutrients.
• How is carbon taken out of the atmosphere

  Carbon is taken out of the atmosphere in the form of carbon dioxide by plants during photosynthesis.
• What happens to carbon when a primary consumer eats a plant?

  When primary consumers eat a plant the following may happen to the stored carbon:

  • Carbon compounds in the plant are digested and used to build new carbon compounds which are stored in the animal's tissues
  • Some of the carbon compounds may be used by the consumer in respiration, releasing carbon dioxide into the atmosphere
• How is carbon returned to the atmosphere in the carbon cycle

  Carbon is returned to the atmosphere when it is released as carbon dioxide by the following processes:

  • Respiration in plants and animals
  • Respiration of decomposers, e.g. bacteria
  • Combustion of fossil fuels or other organic matter, e.g. wood
  • Reversal of the dissolving process by which carbon dioxide dissolves in the oceans
• What is the role of combustion in the carbon cycle?

  Combustion releases carbon dioxide into the atmosphere. This occurs during the combustion of fossil fuels, or of other organic matter such as wood.
• fossil fuels releasing carbon dioxide

  Fossil fuel use releases carbon dioxide into the atmosphere by the process of combustion. This raises the atmospheric carbon dioxide concentration.
• What is the impact of mass deforestation on the carbon cycle?

  Mass deforestation (cutting down many trees) affects the carbon cycle as follows:

  • It reduces the number of trees carrying out photosynthesis so less carbon is removed from the atmosphere
  • It is often followed by combustion as trees are burned, increasing the addition of carbon to the atmosphere