Photo of Chernobyl Tree Rings...

[Plantman]

Originally Posted by MN Renovator

What does it all mean? From what I understand early annual wood growth is lighter and slower late summer/fall growth is darker. Is there any information on the effects with a detailed explanation of what is happening?

I am not sure about the effect of radiation, but wood is lighter early in the growing season because conditions are better, mostly abundant moisture, resulting in large cells. As the season progresses, the cells are smaller until trees go dormant in the fall. The process starts over the next spring, giving trees "rings", one for each growing season. If radiation slows growth or makes cells smaller, it could result in darker wood, but only due to cell size, not an actual change in the color of the wood.