Fun with Science Club®


			Forests cannot erase the impact of human activities. Beth Tyler 06.01.01 Plants grow using energy from the sun and carbon dioxide from the atmosphere. Their leaves and bark (if it’s a tree) are made from the element carbon, found in the compound carbon dioxide. In recent years, humans activities have increased the amount of carbon dioxide in the air. Too much carbon dioxide in the air is dangerous because it increases temperature. Many people, including many scientists, thought that trees and other plants in forests could help decrease the amount of carbon dioxide in the air. Plants could take carbon dioxide from the air to make leaves and bark. When the leaves fell to the ground, their carbon would go into the soil. In this way, many people thought plants could help store excess carbon dioxide in forest soil. Two American scientists decided to experimentally test this hypothesis. They set up experimental forest plots in North Carolina and planted loblolly pine trees (Pinus taeda). They enclosed the forest plots and pumped carbon dioxide into them for three years. The trees did take up a lot of the carbon dioxide. Most of the carbon dioxide they took went into making leaves that fell to the ground. However, the carbon from the leaves that fell to the ground did not go deep into the soil like many people hoped. Instead, it stayed near the surface and was released back into the air. The forest did decrease the carbon dioxide in the air, but not as much as people predicted. This means that forests will not be able to significantly decrease carbon dioxide in the air.


			Schlesinger, William H., and John Lichter. 2001. Limited carbon storage in soil and litter of experimental forest plots under increased atmospheric CO2. Nature 411: 466- 469.