OK, we have looked at the roots. Now, what about the leaves? The leaves are involved in the greatest wonder of the ecological world; photosynthesis. This stuff is very cool. Without this process, there would be no vegetation on earth. We would not exist. The earth would be a dead rock floating around in space. (Some scientists will call me out on this and say there would be some slime mold or something weird like that that would grow, but hey, I’m trying to keep it simple). Photosynthesis is the process where solar energy is converted to chemical energy. Carbon dioxide, water, and sunlight are used to produce glucose, oxygen and water. The chemical reaction is 6CO two, 12H two O plus sunlight ---converts to C two H twelve O six and 6 O two and 6H two O. Which means carbon dioxide and water plus sunlight converts in the leaf to glucose (sugar) with oxygen and water given off. Solar energy is being converted to chemical energy.
The minerals and nutrients along with the glucose and water combined with the biological process of cell division and all the other wonders of growth make a tree, shrub, flower, alfalfa, green bean, corn plant and grass plant that feeds wildlife, dairy cows and grass-fed beef. This stuff is the real deal, not science fiction.
So, you had your dry firewood (clean wood, no paint or wood preservatives) stacked up. You’ve handled it 3, 4 or 5 times now and it’s finally made it to the stove. The final heating cycle you get from the wood is when you burn it. Now you ask, what is the burning process?
Living things are made of oxygen, carbon and hydrogen along with all the minerals that we got from the roots and the glucose from the leaves. When wood gets hot it, the chemical bonds of the cells and structure of the wood start breaking down and they releases gases; hydrogen is one of them. This process is called pyrolysis. The released gases, burn due to the addition of oxygen from the air. Parts of the wood like sap and resins have greater deposits of glucose which is a volatile compound, making it very flammable. The carbon and minerals are resistant to burning. That’s what your ash is composed of, the left over products of combustion that didn’t burn, carbon (charcoal) and minerals, which added together we call ASH. Depending upon the temperature in the woodstove, more or less of the carbon compounds get burned off. The high temperatures due to increased oxygen, burn off more carbon leaving only minerals. Now you know what ash is! So what do you do with it?
Rich Redman is a retired District Conservationist for the USDA Natural Resources Conservation Service and an avid outdoorsman. His column will appear regularly. He may be reached at firstname.lastname@example.org.