Growing Up - My Trunk

A cross-section of a tree showing tree rings and bark.bark
Tree Trunk illustration.

The trunk of the tree has several layers:

Our first layer - the outside layer - is the bark, which protects us.

A thin layer just inside the outside bark is our new bark (called "cambium bark"). This new bark contains active cells, which are our living part. These cells divide constantly during the growing season, and they grow to form the layers called tree rings.