~From Roots to Shoots~

What is wood? Simply put, wood is the fibrous material beneath the bark – and so much more! Wood is a complex system of tissues, each with different functions. It provides structural support to keep trees upright, a transport network for water and nutrients, and storage capabilities.

The heartwood of a tree, whose main function is structural support, is formed by old xylem. Xylem is essentially a bundle of straws held together by a “wood glue” known as lignin. Lignin is the chemical that gives wood its strength. Xylem transports water and nutrients up from the root system and disperses it to the leaves and stems.

The second component of wood is the cambium. This vascular layer, only one cell thick, builds out the girth of the stem. The cambium creates new xylem inward, and phloem outward. This process creates the growth rings found inside trees which can be used to measure the approximate age of the tree.

Phloem is the outer layer of tissue, just underneath the bark. This region of the wood moves sugars and nutrients from the leaves to storage areas in the trunk and root system. The older sapwood cells move toward the center creating the heartwood. Certain species develop unique figure and grain patterns. These variations in heartwood make them prized for woodworking; basswood for duck decoys, black walnut for furniture, and cherry for fine woodwork.

Now the next time you pause to look at a tree, you’ll understand a little more of what’s living on the inside.