Q: Sitting in traffic I saw an oak with a base ten feet around that splits into two trunks five feet from the ground. Are there the same number of rings in the big base as in the two tall forks?

A: No, the two smaller trunks have a few less rings than the base trunk. The two probably resulted from equally vigorous sprouts that occurred at the 5-foot level of the seedling oak several decades ago. The base of the tree has rings that formed when it grew from the original acorn. The two trunks began forming rings when they started extending.