Q: Do tropical trees have rings like their northern brethren?
A: In many cases, no. Rings in trees are caused by changes in the seasons. In the spring, the cambium--the region of cell division in a tree trunk--produces large, thin-walled cells. In the summer, when water becomes more scarce, the cells become smaller and have thicker walls to conserve water. The summer growth therefore looks darker, and the alternating pattern of light and dark bands is what we call tree rings. In the tropics, there are no seasons, so most trees do not produce rings.