The trunk of a large tree is cylindrical, which is a common phenomenon that everyone knows. Looking around us, whether it's trees, shrubs, or large or small trees, it's rare to see square, triangular, or other special shapes of trunks. Interestingly, the leaves, flowers, fruits, and seeds of different plants often vary greatly, but the trunks all remain cylindrical, with little change in shape. In nature, any species that can survive for a long time and maintain its morphological characteristics over time always has its rationality, and cylindrical trunks are no exception.
We know that the circle is the most efficient shape. That is, among materials of the same size, the area of a circle is the largest among all shapes. Since one of the main functions of a tree trunk is to connect the upper and lower parts and transport water and nutrients to various parts of the plant body, a cylindrical trunk can achieve the maximum transport efficiency with the least material. In fact, not only cylindrical trunks are like this, but also the round water pipes and gas pipes we often see in our lives are designed to achieve the purpose of using less material and having a large flow rate. Cylindrical shapes not only have the advantage of transport efficiency, but also have the advantage of supporting function. It can be imagined that the above-ground part of a plant has a large crown, and if it is in autumn and there are many fruits on it, it needs a particularly strong trunk to ensure that the tree can stand upright, and the advantage of a cylindrical trunk is that it has a strong supporting force.
In addition, the cylindrical shape of the trunk also brings greater safety and protection to the plant. We know that the nutrients of a tree are transported to various parts of the body through the cortex in the bark. If the cortex is interrupted, it will inevitably lead to the death of the tree. The trees we often see are perennial trees, and in their long life, they often suffer from many external injuries, especially from natural disasters. In harsh natural environments, if the trunk is square, triangular, flat, or with sharp edges, it will be more vulnerable to external impacts and damage. However, the cylindrical trunk is different. When the wind carries dust and debris, no matter from which direction it comes, it is easy to sweep along the tangent of the circle, greatly reducing the degree of damage.
In summary, all living beings in the world always develop in the direction that is most adaptive to the environment for survival, and their morphological characteristics are often a reflection of their adaptation to the natural environment, and the cylindrical trunk is no exception.