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The Terrestrial Carbon Cycle

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The Terrestrial Carbon Cycle

Carbon moves through the terrestrial realm through five main processes, which are represented as blue arrows in the figure below:

Schematic illustration to show terrestrial processes of carbon flow: photosynthesis, litter fall, plant respiration, soil respiration, run-off
Carbon Flow in Terrestrial Reservoirs
Click for a text description of the Carbon Flow in Terrestrial Reservoirs image.

The image illustrates the carbon cycle in a terrestrial ecosystem. It features a forest with trees and grass above a soil layer. Arrows indicate carbon movement:

  • Photosynthesis: An arrow from the sun to the trees shows plants absorbing carbon dioxide during photosynthesis.
  • Plant Respiration: An arrow from the trees upward indicates carbon dioxide release through plant respiration.
  • Litterfall: An arrow from the trees to the ground shows carbon transfer via falling leaves and organic matter.
  • Soil Respiration: An arrow from the soil upward represents carbon dioxide release from soil microbes breaking down organic matter.
  • Run-off: An arrow from the soil outward illustrates carbon loss through water run-off.
Credit: David Bice © Penn State University is licensed under CC BY-NC-SA 4.0

We will briefly explore these processes, beginning with photosynthesis.