The Vascular System of a Tree

The vascular system of a tree deals with how food and water travel between the roots and the leaves.  We know that, without water and food, our trees would die. A tree must have a way to absorb water and food and distribute it to other parts of the tree, right?

Water and food travel up from the roots via a system of tubes called the xylem. Sugars made during photosynthesis travel down from the leaves through the phloem. Each year, new layers of xylem and phloem are added to the tree. The new layers exist along with the old as the tree grows.

We know that trees need oxygen. Oxygen needs to be available to a tree’s root system. This chemical element needs to be available in the soil. Oxygen can be lost when soil is compacted or waterlogged.  One of the functions of the roots is to take water up from the soil and send it to the leaves to be used during photosynthesis. (For more on photosynthesis, please visit our blog post on the subject here.)

Tiny root hairs perform this function so that photosynthesis can occur. They absorb water. These hairs can wear out pretty quickly and are constantly being replaced. We know that water is pulled up through the tree via transpiration. It is used in photosynthesis and then released into the atmosphere, along with oxygen. This is done via the stomata, tiny pores that are located on the underside of leaves. Stomata create their own tiny moist atmosphere when they’re open. When water is released through the stomata, more is pulled up from the roots like liquid through a straw.

Some trees have the ability to close the stomata during stressful times like drought. This helps them to reduce water loss and protect themselves. However, they can’t stay shut forever or photosynthesis will not occur. Chlorophyll, the green pigment found in leaves, is located in cells called chloroplasts. This is where photons of light are captured and, through a process involving water and carbon dioxide, sugars are made. The sugars are sent down to the roots of the plant through the phloem.

That’s basically what the vascular system of a tree does. It sends water up and food down. Do you have any questions? We encourage you to ask them on our Facebook page so our knowledgeable community can get in on the conversation. If you notice problems with your tree, please don’t hesitate to contact us at 512-341-8888. We are always happy to help at Austin Tree Service.