Why are forests important in relation to carbon?
Carbon exists in the atmosphere as CO2, an important greenhouse gas. Greenhouse gases trap heat that is radiated from the earth’s surface, thereby warming the atmosphere. Since the industrial revolution, there has been a marked increase both in emissions of CO2, and in atmospheric CO2 concentrations. Plants in forest ecosystems convert CO2 into organic carbon compounds through photosynthesis and fixate this carbon in organic material, such as wood, leaves and roots. Alternately, carbon is released back to the atmosphere by forests through respiration, decomposition and combustion. When the carbon gained by photosynthesis exceeds what is lost due to respiration, decomposition and combustion, the ecosystem is a sink for carbon from the atmosphere. When the opposite is true, the ecosystem is a source of carbon to the atmosphere.
