Why do trees have bark

These include temperature extremes, storms, attacks by animals, diseases, and insects. Some trees even have developed extra thick bark which can protect them from the effects of brush fires. Bark also helps trees distribute water and nutrients, and they cannot live without it.

The conductive cells of the phloem differ from tree to tree. The phloem on the inside of the bark is separated from the outer living layer of the heartwood, or xylem, by a layer known as the cambium. If bark is damaged around the circumference of the trunk, the tree is in real trouble. The phloem can no longer do its job of transporting sugars, and the tree may die. Voles often eat the bark at the base of young trees, killing young saplings.

The bark of trees including aspen and willow is an important food source for the European beaver. While all this bark feeding can be destructive to individual trees, it is worth taking a step back. From an ecological perspective it shows how bark can support a wide range of different species. Also, when a tree is killed or harmed by bark damage, valuable dead wood habitat can be created for fungi, insects and many other organisms.

But when we take a closer look we can see how every surface, nook and cranny in the woods can provide food and shelter for myriad living things. In this way bark also helps increase the biodiversity in a forest. Our vision is of a revitalised wild forest in the Highlands of Scotland, providing space for wildlife to flourish and communities to thrive. Plant a tree Donate. Search for:. Tree bark. And a whole host of other species make use of this niche in the forest ecosystem. The visible part keeps moisture in and keeps infection out.

What is bark? Bark as protection The outer cork protects the tree from the elements — from scorching by the sun or drying by wind.

Bark as a habitat Cracks in bark provide great habitat. Food for wildlife Bark does a great job of protecting the tree. Sources and further reading Brown, R. Animals — Tracks, Trails and Signs. Hamlyn: London. In general, the capacity of most woody plant species to photosynthesise through stems or branches is limited to the very early stages of growth.

According to Dr Miller, as the branches thicken through secondary growth, they become woody and develop the protective tissues of the periderm, which are not usually photosynthetic. Banner Image: Forest trees. Picture Vovan via Shutterstock. Pursuit home All sections. Tree bark has a lot of different components with extremely difficult scientific names and uses. I will try to go through the major components of tree bark as briefly as possible. What most people know as the bark of a tree is known as the rhytidome.

It is the most outer layer of a tree and if you were to peel off the first layer from any tree, it is the rhytidome that would come off. This is known as the outer bark. The inner bark on the other hand consists of the secondary phloem and secondary cortex. The inner bark components comprise cells that are still alive. Though both the inner and the outer bark are outside the vascular cambium.

The vascular cambium being the growth layer. The phloem is responsible for transporting the food to the entire plant. But it has a short life before it gets converted into rhytidome. Another component of the bark is the periderm, this is further divided into sub-layers. The function of this component is protection against bacteria and insects. It also prevents water loss from the tree. You must have noticed that most of the barks are rugged and have cracks.

When a tree is younger, they sometimes have very smooth barks. These usually crack up as the tree gets older. On the other hand, there are some species that have smooth barks throughout their life span. You might come across a tree with peeling barks. They look like loose hanging skin. This usually happens when the growth rate of the tree and the bark are not the same. When the tree is growing at a faster rate compared to its bark, the outer layer can start coming off.

Pine or even a Paper Birch is an example where the outer layer starts peeling off in curly strips. Every tree has lenticels, they are the pores that are responsible for transporting oxygen and CO2 throughout the outer bark. In some trees, they are visible in different shapes and sizes. Yellow Birch, for example, has horizontal lines which are actually its lenticels. Bigtooth Aspen on the other hand has lenticels shaped like diamonds. A rough bark entails that the rhytidome has gaps or cracks within it.

There are two major types of ridges, intersecting or parallel. White Ash has intersecting ridges while Northern Red Oak has parallel ridges. The only difference between scales and ridges is the way that the outer layer left gaps within it.