Trees are often all around us and they are essential to our ecosystem. Even so, they’re easily taken for granted. There are many key facts about trees that people aren’t quite clear on. One in particular — how trees grow in the first place? This seems to be particularly puzzling. Only experts, like those at Technical Arboriculture, really seems to know the answer to this simple question. After serious study, however, many interesting details about the mechanisms of tree growth have been laid bare.
1 – Plumbing
You can think of trees as a collective of plants that grow annually. Each group grows at the end of a large plumbing system that’s completely interconnected. Those plants are referred to as twigs. Twigs give way to the leaves, fruit and flowers that give trees their traditional elements of beauty. When set aside, they’re not particularly different from any other plant. The key difference is how they all connect via a large system of branches. This system is quite comprehensive, with water, sugar and hormones flowing throughout to regulate the growth and evolution of the tree as a whole.
2 – Water Flow
When it comes to the oldest branches, only the thinnest external layer is comprised of living tissue. Everything else is made up of completely dead cells. The cell walls give way to a strong and supportive structure that’s essential to how tall the tree can stand. Moreover, the spongy nature of the cells takes water through every branch, all the way from the roots to the leaves.
Trees use water in several key ways. Along its trajectory along the branches, the water is filtered so that all its minerals and nutrients can be utilised. Keeping a consistent flow is achieved by the evaporation of the water that reaches the surface of the leaves. The sponge is then dried out once more, allowing the process to begin all over again.
3 – Sugar Flow
Not only do they help water evaporate, leaves are also vital to the act of photosynthesis. That ties into the way that sugar flows throughout a tree. Once energy has been taken in from sunlight, leaves bind carbon dioxide and water in order to create sugar molecules. The resulting sugar is then stored and used for energy. The actual flow of the sugar resides in the branches’ living tissue. If there’s a cell that needs energy in the thin layer below the bark, a corresponding leave will help fill it up. The roots, branches, buds and trunk are all connected. This is essential to how trees grow successfully.
4 – Hormone Flow
As sugar and water flow throughout a tree, essential hormones are also distributed. Just look at apical meristems for example. Referring to branch tips responsible for new cell growth, these produce the Auxin hormone that allows for growth regulation. Hormones of this type dictate how certain branches will lay and that’s just one example of many.
5 – Twigs
Everything above lays the basis for how the growth of a tree is managed. The next important attribute to examine lies within the twigs. The role of twigs is certainly influenced by the hormones running throughout the plumbing system, but they’re still quite individualistic. Twigs begin their lives as buds, every single branch and leaf base gives way to the growth of a bud. Twigs start from there, in an embryonic stage of sorts, complete with a protective cocoon that can even withstand harsh winter conditions.
6 – Senses
A staggering amount of the twigs mentioned above are grown each year. In a way, you can think of twigs as the “eyes and ears” of trees. They obviously can’t do those things in particular, but there are indeed a number of senses present and they play an integral part in dictating the wheres and hows of how the tree ultimately grows.
One important example is the sense of balance which trees utilise in order to grow in accordance with gravity. This is referred to as gravitropism by biologists. The result is the interesting manner in which trees grow upwards despite their roots travelling down through the ground.
As detailed above, sunlight is obviously of great importance to trees since it facilitates their food supply. As such, trees also have a sense for different light conditions. Twigs can sense several different hues or shades of light. If there’s not enough light being sensed, the branches will grow at an even faster rate in hopes of finding more.