As you just saw, the absolute thickness of narrow and wide rings can vary among trees exposed to the same conditions. However, the pattern formed by the sequence of narrow and wide rings is the same.

For a comparison of rings from tree to tree, the pattern of thin versus wide rings must be recorded on a standard graph. This type of graph is called a skeleton plot. Skeleton plots show tree growth in years that stand apart from other years, because the tree experienced either greater than average or less than average growth.

  !   Click the button to see an animation that explains how to make a skeleton plot. Follow the process outlined in the tutorial to construct a skeleton plot for Core 2, shown below.