Because it takes up so much moisture and plant food, sapwood rots much more quickly than heartwood.

The sapwood really acts as a pipe line to carry water from the roots to the top of the tree.

In some of our largest trees the moisture is raised as high as 300 feet or more through the sapwood.
Strange though it may seem, trees fight with each other for a place in the sunlight.

Sprightly trees that shoot skyward at a swift pace are the ones that develop into the monarchs of the forest.

They excel their mates in growth because at all times they are exposed to plenty of light.