New study refutes Leonardo da Vinci’s ‘rule of the trees’

2023-09-19 17:04:28

Illustration of Leonardo in his description of the ‘rule of the trees’ – BANGOR UNIVERSITY

MADRID, 19 Sep. (EUROPA PRESS) –

A ‘rule of trees’ developed by Leonardo da Vinci to describe how to draw trees has been widely accepted by science in modeling trees and how they function.

But scientists from Bangor University in the UK and the Swedish University of Agricultural Sciences (SLU) have discovered in new research that This rule contradicts those that organize the internal structures of trees.

Da Vinci’s interest in drawing led him to observe the size proportions of different objects, including trees, in order to create more accurate representations of them. To correctly represent trees, he perceived the so-called “rule of trees”, which states that “all the branches of a tree, at each stage of its height, are the same thickness as the trunk when they are together.”

It had been thought that Leonardo’s “rule of trees” could also apply to the vascular channels that transport water through a tree, with the size of individual channels decreasing in the same proportion, as the branches become larger. narrow, while continuing to increase the volume of the trunk. This rule had been accepted as part of the theory of metabolic scaling.

But scientists at Bangor University and SLU have shown that this model is not exactly correct when applied to the internal vascular structures of trees. The study has been published in Proceedings of the National Academy of Sciences (PNAS).

For water and nutrients to move efficiently through the tree, from the root to the tip of the leaf, the vascular system must maintain hydraulic resistance.

Rubén Valbuena and Stuart Sopp of Bangor University and SLU have calculated that for hydraulic resistance to work, There comes a point where the rule of trees can no longer be valid.

To efficiently transport fluids from roots to leaf tips, a tree’s vascular channels must maintain a certain dimension to maintain hydraulic resistance. Therefore, the plant has to reduce its volume as it reaches its extremities, causing a greater proportion of capillarity with respect to the surrounding plant mass.

How do you explain it’s a statement Dr. Rubén Valbuena (honorary professor at Bangor University and now a professor at SLU): “Although it is great ‘advice’ for artists, which is what da Vinci intended, Leonardo’s rule of trees does not hold up at the micro level.”

“We believe our calculations further refine metabolic scaling theory and improve understanding of the plant system as a whole. Our new calculations may also explain why large trees are more susceptible to drought and may also have greater vulnerability to climate change“.

Co-author Stuart Sopp, currently studying his PhD in Environmental Sciences at Bangor University said: “One of our aims was to produce a ratio that could be used to estimate tree biomass and carbon in forests. “This new ratio will help calculate global carbon sequestration by trees.”