Trees are all around us. However, many people still have some general misconceptions about how trees grow. “If you study the way trees grow, you’ll find that there are some surprising mechanisms that go into creating these complex plants” says a tree expert at Technical Arboriculture.
You can think of trees as a collection of annual plants. Each tree grows at the end of an interconnected plumbing system, generally known as plants twigs. These twigs create the flowers, fruit and leaves of the tree.
Alone, they are like any other plant. It is their connection to a large system of branches that sets a tree apart. Through these branches sugar, water and hormones are distributed, flowing to and from the twigs. This allows the tree to regulate growth and evolve, creating majestic structures we admire so much.
The Flow of Water
Just beneath the bark, on older branches, there is a thin outer layer which is living tissue. The rest of the tree’s branch is made up of old dead cells. These cells provide the structural support the tree needs to remain standing. However, more importantly, the sponge-like structure of the cell walls suck water from the root of the trees and into every branch, all the way to the leaves.
There are several ways that a tree uses water. Water is filtered, all of its minerals and nutrients, as it moves up through the branches. In order for the tree to get enough of the essential nutrients, and to keep a steady flow of water, the surface of each leaf must evaporate water using the heat from the sun. This dries out the spongy layer and allows it to suck up more water from the soil surrounding the tree.
The Flow of Sugar
In addition to evaporating water, the leaves of a tree also need water for photosynthesis. By absorbing the energy from the sun, a leaf can take carbon dioxide and water and bind them to form a sugar molecule. This brings us to the flow of sugar.
A tree uses sugar as a way to store energy. The flow of sugar only takes place in the thin layer just below the bark of a branch and this is the living tissue. The leaves will continue to fill up and the connected cells, that need energy, will take it from them.
The Flow of Hormones
The flow of water and the flow sugars in a tree are also used as a way to distribute hormones. Take the tips of a branch that grow new cells or the apical meristems. They produce a hormone called Auxin, which regulates growth. This is the hormone that tells the branches lower down on a branch to lay low.
Now that you know how a tree is able to regulate its growth on a grand scale. Let’s take a look at twigs. Twigs take their orders from the tree’s hormones which are flowing through a tree’s plumbing system. However, they are individualistic plants. For a twig, life starts as a bud.
A bud grows at the end of each branch and the base of each leaf. The bud contains twigs’ embryonic beginnings, encapsulated in a protective cocoon to help it survive the upcoming winter.
Each year, a large number of twigs grow from buds. Twigs are a trees eyes and ears. While a tree can’t hear, they actually have just as many senses as animals. A twig, using its senses, can determine where the tree should grow.
The trees sense of balance can allow it to grow contrary to gravity. This is called gravitropism. It allows a tree to grow up and its roots to grow down.
Light is as important to trees as their food. That’s why it’s not surprising that trees have developed a superior sense for light. Twigs can sense many hues of light. If there is too little light, a tree will begin to grow vigorously in the hopes of finding it.