Tree Structure

By June 1, 2017 No Comments

Tree structure

We take trees as fore granted, but they play an important role towards humanity.

  1. The tree structure works in one complete harmony to permit photo synthesis to takes place. Each element of the tree structure uses its functionality so that the leaves will absorb carbon dioxide and gives away oxygen.
  2. This photo synthesis also helps to produce sugar that will result in the tree’s fruit.  Today we will be looking on the elements that makes the tree structure.

There five elements that form a tree structure:

  1. Rooting system
  2. Main trunk
  3. Branches
  4. Leaves

We will have a quick look on these elements that will give us a clear vision of each and every element and its importance.

Rooting system

Although all five elements in a tree structure are equally important, but one can say, that the roots system is the most important of them all.  The roots are the main point that will determine the tree growth.  Healthy root system in the right soil condition will result in a healthy tree.  Nutrients and water moisture present in the soil will be absorbed by the hair roots and be piped into the tree towards the leaves.

The absorption of water and nutrients from the soil is just one purpose the roots are used for.  The flow of water and nutrients will encourage the photo synthesis and the photo synthesis will also produce sugars in the form of a fruit.  Roots also helps to anchor trees to the ground, prevent them not to fall on very windy days.

One can say that roots are the hidden parts of the tree balance: a healthy large tree is the result of a healthy large rooting system hidden under ground.  On the other hand, a small unhealthy tree is the result of unhealthy rooting system.  The tree foliage balances the rooting system.  Knowing this, in bonsai, we tend not to remove more than 20% of the rooting system when re-potting.  In addition, a problem in the rooting system, that is, root rot, will result in an unhealthy tree or die back branches.

A frequent question is: ‘How do roots grow?’  The answer is that there are two ways on how roots grow:

  1. A straight downwards root exactly under the trunk is called tap root.
    1. Their main purpose is to anchor the tree to the ground.
  2. All other roots grows horizontally, and they are called lateral roots.
    1. Lateral roots spread outwards seeking nutrients and moisture.
    2. Hair roots absorb and dissolve water and nutrients from the soil, then send it to flow through the truck, branches towards the leaves.

On the contrary of a tree in nature, bonsai trees are potted in small pots, thus having a restricted area to grow, so nutrients and moisture should be present.  A bonsai tree should have what nature offers to trees in nature

The Trunk

The main trunk is the strongest structure of the tree.  It has is five different layers, all with a different purpose that will help the tree to grow and stay alive and healthy.

  1. The outer bark:
    1. It protects the trunk while keeping it moist in and does not permit rain moisture to enters.
    2. It is also a good insulator against cold or heat.
    3. The outer bark also prevent insects from entering inside the tree core.
  2. The inner bark:
    1. It is the piping system through which food passes.
    2. These piping system is called the ‘Phloem’.
    3. This has a short term and when it dies out, it becomes part of the outer bark.
  3. The cambium layer:
    1. This layer is what makes a tree to grow thicker, since annually it produces new wood holding the phloem to help food to pass through.
    2. The cambium layer also produces hormones called ‘Auxins’ that encourage the growth of new cells.
    3. These auxins are produced by the new leaf buds.
  4. Sapwood or Xlyem:
    1. Also a new wood that permits water to pass towards the leaves.
    2. This also has a short life, and when it looses its vitality, the sapwood is turned to heartwood.
  5. Heartwood:
    1. It is the inner part pf the tree, the part that support the tree.
    2. As long as the outer layers remain intact, the heartwood will not decay.
    3. The heartwood keeps bonded together bin the form of cellulose fibers by ‘Lignin’ a type of natural chemical glue.


First branches, secondary branches and tertiary branches or twigs, are extensions that grows from the main trunk, permitting nutrients to flow from the roots to the leaves and the sugar created by the photo synthesis to flow from the leaves to the roots and the fruits.  Branches also plays an important role in the overall design of a tree.   Various tree species have different branch constructions, such as pines and cypress trees.  The growth of the branches varies according to the location the tree is planted or the type of species.  One should follow some rules when it comes to trim branches in bonsai.


Leaves have an important role to maintain the plant or tree alive, one can say that they are the powerhouse of a tree or plant since they are the essential thing that does the photosynthesis.

There are two types of trees:

  1. Conifers
    1. These evergreen type of leaves consists of mostly needle-leaved or scale-leaved.
    2. The type includes: pines, spruces, firs, larches, yews, junipers, cedars, and cypresses.
    3. In bonsai, conifer trees should maintain their needle-leaves
  2. Deciduous
    1. Trees that will lose their foliage at maturity, and they achieve maturity seasonally.

Various species of trees have various types of leaves.  Leaves varies in sizes and shape, and some also have the ability to change color.  One example is the Japanese maple tree.  This species has the ability to change it’s green leaves to reddish orange in winter.


Martin Abela

Author Martin Abela

More posts by Martin Abela

Leave a Reply