A tree trunk may look pretty ordinary to you, but there’s much more to it than meets the eye. Every day, all day, there is an incredible amount of activity going on behind that layer of bark, moving nutrients, water, and energy back and forth from the roots to the leaves. But the trunk does even more than that; it also contains the tree’s most important defenses against disease, insects, fire, and the other influences that threaten to harm it. Here’s a little tree trunk science from your arborist in Charleston, SC.