Bark is like a trees’ armour. It shields the tree from hungry animals or insects, stops it from getting burnt, or drying out, when the sun is strong and gives it strength to keep standing on a windy day.
And that’s not all! Bark also contains chemical compounds which defend the tree against bacteria, fungi and insects, and help it heal when it is injured. Because of these valuable chemicals, people traditionally used bark for many things including medicine, spices, making cloth and tanning leather. The bark of almost every Kenyan tree had an important use. See the trees below for some examples.
The outside of the bark is made of dead cells. Inside this layer is the sugar pipeline, the phloem, which (like our veins) carries nutrients to all parts of the tree. An inner layer, called the cambium, produces new bark cells.
Removing tree bark hurts the tree and can even kill it. So never remove the bark yourself!
As a tree grows, its protective armour becomes too tight. The bark begins to fall off like a snakeskin, to be replaced by new bark underneath. The different ways that bark cracks or falls off the tree can help you to tell one tree from another. When you come across a new tree, take some time to explore its bark. Look at the way it grows and cracks, feel the surface (unless it’s a hairy Nettle Tree!), take a sniff to see if it smells... Here are some different types of bark to look out for.