It is my understanding that every ring seen in the cross section of the trunk of a tree indicates the number of years that tree has been alive. During years where the tree survived significant trauma, the rings change shape and width, in a sense telling it's life story. This is a slice of one of four Blue Spruce trees from our front yard that succumbed to some sort of blight within the last few years and had to be taken down last fall. They were majestic trees when they were healthy.