Do you know how tall the tallest tree in our country is?
Theoretically, how high can a tree grow? Why do some botanists indicate that trees can only grow up to 120 meters? What exactly limits them?
The tallest tree in my country is a yellow-fruited fir with a height of 83.2 meters. In May of this year, the Chinese Academy of Sciences team discovered it in a virgin forest in Chayu County, Tibet.
In order to get more accurate results, the staff used drones to measure many times. What is the concept of an 83.2-meter tree? In layman's terms, this height is roughly equivalent to the height of a 30-story building.
You can try to imagine what it feels like to stand on the 29th floor and reach out to pick leaves.
How tall is the tallest tree in the world?
It is said that in 1871, forestry personnel discovered a 132.6-meter-high almond tree on the banks of the Watt River.
However, this data was obtained by a forestry personnel through simple measurements and is not recognized by scientists. What was accurately measured was a 114.2-meter-high Eucalyptus almond discovered in 1881. Today's tallest tree in the world is a 116.07-meter-high redwood tree located in Redwood National Park in California, USA.
Today, the top ten trees in the world are basically 110 to 120 meters in height. The first-ranked "Hyperion" is 116.07 meters tall; the tenth-ranked Mennosido, located in Montgomery Forest, California, is 112.2 meters high. The difference between the two is only 4.05 meters.
The giant tree we are most familiar with, Eucalyptus almond, is generally 70 to 114 meters tall. The North American redwood, recognized as the tallest tree species in the world, can generally grow to about 110 meters in its native coast of California.
Trees of around 110 meters are often found around the world. However, so far, people have not found a tree exceeding 20 meters.
120 meters is really a hurdle that a big tree cannot cross. Why?
Dr. George Heller of Arizona State University in the United States conducted research on trees up to 100 meters high around the world. It was found that these giant trees, which are over 110 meters tall, all have a serious problem: their leaves are extremely short of water.
Generally, this happens only to plants growing in extremely arid deserts. You must know that these big trees generally live in places with abundant water resources.
Water needs to overcome the gravity of the earth and the friction of the tree tissue from the root system to the leaves at high altitude. Therefore, Dr. Koch believes that the maximum height of trees on Earth is 122 to 130 meters. Beyond this height, it is difficult for water to reach the top of the trees.
We know that water pumps are needed to provide water to buildings. People who have lived in old residential complexes built before should be well aware that the higher the floor, the lower the water pressure.
Because the water pump at that time was not powerful enough and the pressure generated was insufficient. Therefore, while tall buildings continue to be built, engineers are also designing more powerful water pumps to solve the water supply problem. There is no water pump in the big tree, so how does it send water up to a height of 100 meters?
Plants mainly rely on the pulling force generated by transpiration to transport water. Simply put, transpiration is when water turns into vapor and evaporates out of the leaves. Transpiration creates a transpiration pull.
When a part of the water evaporates from the cells, the concentration of the cell solution will rise, forming a concentration difference with the surrounding cells. At this time, water will flow from cells with low concentration to cells with high concentration. In this process, formation of Transpiration pull.
So, what is the maximum pulling force of transpiration and ?
The roots of plants absorb water from the soil, pass through the vessels in the trunk, then enter the leaf veins, and finally enter the mesophyll cells; in the plant body, water forms a continuous whole.
To put it simply, when the water in the mesophyll cells at the top evaporates, it will pull the water in the vein cells, the veins will pull the water in the conduits, the conduits will pull the water in the roots, and the roots will absorb water from the soil.
When plants transpire, since water forms a continuous whole within the plant, a stable negative pressure will be generated - the pressure difference between the top and roots of the plant. This negative pressure can pull a water column of 10 atmospheres, and the water column of one atmosphere is 10.4 meters, so the water column of ten atmospheres is 104 meters.
In other words, more than 100 meters is the limit of transpiration pulling force to transport water. This is why Dr. George found that the leaves of trees more than 110 meters high are extremely short of water.
We can conclude that the limit of transpiration pull determines the limit height of water transport, and finally limits the limit height of trees. Botanists therefore believe that under natural conditions, it is unlikely that trees will cross the 120-meter "hill".
Of course, in addition to the influence of water, the main reason that limits tree height is genes. Therefore, most of our common trees can only grow to 20 to 30 meters.
