Date: Mon, 16 Jun 2014 09:55:39 -0400
From: “John R Dykers”
Subject: CO2 sequestration and tree growth rates/age
To sequester carbon, trees have to form carbon compounds, primarily wood. This is done by photosynthesis in the leaves, and there are more leaves on trees with a large canopy like big old trees. As I understand it the transfer of that CO2 into wood is less in very small trees (newly planted, for example) but the rate of growth increased with tree size up to a point. That point in pine trees is about 18-24 inches in diameter, beyound which this creation of wood slowly decreases. Others will have to educate us about different species, but I have been told that my hardwood forest will not make much more wood even if it were to be left to grow unattended for the next 100 years. Maybe this is primarily economic harvest value, not just carbon sequestration. I have a ‘park’ area with about 20 3ft diameter oaks and plan to harvest 8 with good saw logs and save the others for shade.
We often forget that the grass we grow also sequesters CO2; mow that lawn and let the clippings rot to put organic matter back into the soil. Here also is a trade-off; leaving the grass about 3-4 inches long helps keep it (fescue) healthy and allows the clippings to slip to the ground to rot, BUT also makes it easier for ticks to move from the taller grass onto your feet!
As Michael Burke pointed out, nature is complex, and we learn new insights with every investigation. There is soooo much ‘information’ available we all want to evaluate carefully.
John Dykers
let’s strive to be more knowledgeable and less opinionated.