(Can’t have one without the other)
By Gary Salmon
As a part of the Forestry Building display at this year’s state fair there was a very simple (as if anything chemical is simple) explanation of the relationship between photosynthesis and today’s hot forestry topic, forest carbon sequestering. In fact, I wanted to call the seedlings we were parting with “carbon sequestering units,” but that seemed a bit “Star Trek”-ish for some. In any case, a couple of points need to be made here related to just where and how these processes work, for as the title says, one can’t do without the other.
Carbon dioxide is exhaled by animals, created by the decomposition of plants, and released during the combustion of fossil fuels. In a leaf, carbon dioxide comes in contact with water and nutrients that have been drawn up from the soil by the tree roots. In the presence of chlorophyll (green part of leaf) and sun energy, the carbon dioxide is combined with the water creating a sugary-like food for the tree.
(Inside a leaf)
6 CO2 + 6 H2O C6H12O6 + 6O2
carbon dioxide water sugars oxygen
The cambium cell layer is the growing part of the tree. It takes the sugar created in the leaves and transforms it into wood for continued tree growth and of course carbon storage. Carbon sequestering is the process of removing atmospheric carbon and storing it in another form that cannot be immediately released, like wood. The sugars are transported from the leaf down into the woody parts of the tree where the cambium changes it into the wood for tree growth.
(Inside the tree)
C6H12O6 C6H10O5 + H2O
Sugar Wood Water
As long as the tree is alive it will be creating new wood and getting larger each year. However, when it dies or is cut down and used for lumber, it stops growing but does not stop storing carbon until such time that wood decomposition takes over and the wood is converted back into atmospheric carbon. There are many Vermont houses built with wood that contain carbon that was sequestered by trees centuries ago. Harvested wood that is used for long-lived products like furniture, flooring, and building materials stores the carbon as long as it remains as a solid wood product.
