While trees must grow tall and large to get light, there is a mechanical limit to the height that can be achieved while bearing their own weight and maintaining their independence.
However, in reality, trees in nature are very stable, high and large.In other words, thinking that the "mechanics for efficiently overcoming gravity" that trees have acquired in the process of evolution is hidden here, researchers at Hokkaido University have said that "balance of distribution of heavy objects" and "balance of weight distribution" of trees. The relationship of "maximum feasible height" was examined using the theory of structural mechanics.
Considering the influence of branches and leaves of trees, we introduce and analyze a computational model in which the density changes continuously so that trees with various weight distributions can be expressed, and the maximum height at which the weight distribution of trees can grow. Succeeded in formulating what kind of influence it has on.From this result, "increase in the weight of branches and leaves" and "concentration of heavy objects on the upper part" are factors that reduce the maximum height, but even if the weight of branches and leaves is increased, if the heavy objects are concentrated on the lower part. It was found that the effect on the maximum height can be kept small.
Looking at the actual trees based on this, the distribution of branches and leaves is skillful so that the maximum height is reduced by about 1% to 15% compared to the case where there are no branches and leaves. I understood.The weight distribution of the branches and leaves, which is streamlined to secure the maximum height by increasing the number of branches and leaves from top to bottom, is also an arrangement that receives light from the leaves in a well-balanced manner and streamlines photosynthesis. Therefore, it can be said that trees in the natural world have achieved the ideal weight distribution of "securing the height while distributing as many branches and leaves as possible to survive".
It is expected that the results of this research, which clarified the mechanical rationality of trees, will lead to the creation of new structural designs and new materials that incorporate the wisdom of living organisms.
Paper information:[Scientific Reports] Mathematical modeling to determine the greatest height of trees
