Heartwood and Sapwood

Heartwood and sapwood are two types of wood found in trees and woody plants. Heartwood is the innermost layer of wood in a tree trunk, while sapwood is the outer layer. These two types of wood differ in their physical and chemical properties, and they play different roles in the tree's growth and survival.

Sapwood is the active, living part of the tree responsible for transporting water and nutrients from the roots to the leaves. It is usually lighter in color than heartwood, and it contains living cells such as xylem and phloem. The sapwood is located just beneath the bark of the tree, and it is the part of the tree that is most vulnerable to insects, disease, and mechanical damage. Because of its active role in the tree's growth, sapwood is usually softer and less durable than heartwood.

Heartwood, on the other hand, is the inactive, dead part of the tree that no longer conducts water and nutrients. It is usually darker in color than sapwood, and it contains compounds such as tannins and resins that make it more resistant to decay, insects, and fungal infections. The heartwood is located at the center of the tree trunk, and it is the part of the tree that provides most of the tree's structural support. Because of its durability and strength, heartwood is commonly used for building materials such as furniture, flooring, and decorative items.

The transition from sapwood to heartwood occurs gradually as the tree matures. As the tree grows, the innermost layers of sapwood become saturated with resins and other compounds, causing the cells to die and become heartwood. The age at which a tree begins to produce heartwood varies by species and environmental conditions, but it generally takes several years for a tree to produce a substantial amount of heartwood.