What is Heartwood?
As a tree increases in age and diameter an inner portion of the sapwood becomes inactive and finally ceases to function, as the cells die. The inert or dead portion is called heartwood. Its name derives solely from its position and not from any vital importance to the tree. Mineral deposits, gums and resins in the heartwood give a darker color than the sapwood.
What is Sapwood?
Sapwood is living wood in the growing tree. All wood in a tree is first formed as sapwood. Its principal functions are to conduct water from the roots to the leaves and to store up and give back according to the season the food prepared in the leaves. The more leaves a tree bears and the more vigorous its growth, the larger the volume of sapwood required. Hence trees making rapid  in the open have thicker sapwood for their size than trees of the same species growing in dense forests.
Main Differences Between Heartwood and Sapwood
The basic differences between sapwood and heartwood is given below as comparative table.
Sapwood |
Heartwood |
Sapwood is the living part of the tree. It conducts moisture, minerals, oxygen, and nitrogen. |
Heartwood is not a living part of the tree, composed of cells that have been physically and chemically altered by mineral deposits. |
It is not durable when exposed to conditions that promote decay. |
It provides structural strength for the tree. |