What is the function for outer bark?

The outer bark of a tree serves primarily as a protective layer, safeguarding the inner tissues from environmental threats such as pests, diseases, and physical damage. It also helps to minimize water loss and regulates gas exchange through specialized structures called lenticels. Additionally, the outer bark plays a role in insulation, protecting the inner wood and cambium from extreme temperatures. Overall, it is essential for the tree's overall health and survival.