Why can't trees be tall?

The famous Douglas fir in the botanical world is more capable than most other plants. But there is still a limit that it cannot overcome, and a new study explains why.

If growing too high, the tree cannot transport water to the highest lying leaves.

Research shows that in the middle of a height equivalent to a 30-35-story building, the Douglas fir could not bring water higher. This prediction also coincides with the tallest fir tree in the world, 99 meters high (the tallest tree in the world is a coniferous tree in California - 115 meters).

Scientist David Woodruff climbs a Douglas fir.Photo: LiveScience.

"The higher in the Douglas fir tree, it is like going through a drought," said Rick Meinzer, a Forestry Service scientist at the Pacific Northwest Research Station.

Evaporation of leaves entails both water and air bubbles. In the Douglas fir, this transport process depends on dead cells, acting as valves and creating most of the wood of the trunk, preventing air bubbles from spreading through the body. By preventing the dispersion of air bubbles through these valves, fir trees also prevent water from being pulled higher.