The Sum of the Parts Makes Trees Strong

By Mark Gialanella, Community Programs Coordinator


Trees are just like every other organism on earth. They have multiple complex systems, each doing a specific job to ensure their survival. In terms of age, trees are the longest-living things on the planet. The oldest documented tree is a Bristlecone Pine found in the White Mountains of California that is more than 5,000 years old. While most trees do not approach an age close to this ancient pine, they are able to have a very long life.

Several parts of the tree contribute to their ability to thrive including the bark, phloem, cambium, and xylem. The part of the tree that is most noticeable is the bark. A tree can be identified by its bark, which is there to protect the tree from harm. The bark can protect the tree from disease, fire, and pests. The phloem is the next layer inside the tree and is sometimes called the inner bark. The phloem is made up of living cells, and its purpose is to act as a transportation network of nutrients and sugars that are produced by the leaves. The cambium layer is the dividing line between the phloem and xylem. The cambium is very thin and serves as the factory of the tree, producing cells that either become the phloem or the xylem. The cambium is responsible for the growth of the tree. It’s also the favorite part of the tree for beavers to eat due to the high nutrient content. The xylem is responsible for moving water throughout the tree. The water comes up from the ground through the roots, which also secure the tree in the ground. The thick cells of the xylem allow for the transport of water throughout the tree to the leaves.

These few parts offer just a glimpse into the fascinating workings of a tree. Trees are very complex organisms. To learn more about trees and establish your roots as a tree expert, visit the educational resources of the United States Forest Service .


The Mission of the Chattahoochee Nature Center is to connect people with nature. Learn more at