What two layers make up the annual growth ring of a tree?

The annual growth ring of a tree consists of two main layers: the earlywood (or springwood) and the latewood (or summerwood). Earlywood is formed during the spring and is characterized by larger, thinner-walled cells that allow for rapid growth. Latewood is produced in the summer and fall, featuring smaller, thicker-walled cells that provide strength and support. Together, these layers reflect the growth conditions of a tree throughout the year.