83.2 meters! The tallest in China! Can trees achieve "immortality"?

recently

Two records for trees were broken

First, a Bhutan pine tree with a height of 76.8 meters was recorded.

Later, another 83.2-meter-tall Abies yunnanensis was discovered.

Breaking the record of the tallest tree in China

my country's second comprehensive scientific survey of the Qinghai-Tibet Plateau found the tallest tree in my country so far. This is a yellow fruit fir, with a height of 83.2 meters, surpassing the previously reported Bhutan pine (76.8 meters) in Tibet and Taiwan fir (81-82 meters) in Taiwan.

Today we will study:

Can trees grow infinitely tall?

How are trees this tall measured?

Why study big trees?

Giant Tree

Bhutan pine is a tall tree. In the natural environment, the average height of Bhutan pine is 25 meters, so the 76.8-meter tree discovered recently is considered a giant among the Bhutan pine group.

The newly discovered Abies yunnanensis forest is distributed in a belt-like pattern in the mountains and valleys on both sides of the Chayu River in Shangchayu Town, Chayu County, at an altitude of about 2,300 meters. The area is able to preserve such tall and intact virgin forests thanks to the excellent climate and terrain conditions, as well as minimal human interference.

Researchers have found that this community contains a large number of ancient yew trees, which are national first-class key protected wild plants, as well as epiphytic plants such as orchids and ferns, and has important scientific research value and conservation significance.

Can plants grow indefinitely?

Theoretically, plant cells in different tissues retain a certain degree of omnipotence. Because of this, plants have a strong ability to repair themselves. Even if a branch is cut off, or even the entire crown is cut off, new branches and leaves will still grow.

As long as the conducting tissues in the roots, stems and leaves of the plant are not damaged and the leaves can photosynthesize normally, the tree will survive. So in this sense, if the conditions are right, these stem cells exist and different tissues can be constantly renewed, the plant will not die.

However, in nature, it is difficult for plants to live forever . Because as long as time is long enough, all regions will encounter unexpected events. Even if it is not disasters such as mudslides, hurricanes, earthquakes, and pests and diseases, there will be ice ages and long droughts. Even if you are lucky enough to avoid all natural disasters, you still have to face competition from new species. Therefore, it is impossible for big trees to live forever, and no big tree can grow indefinitely.

How to measure the height of a tree

In measuring the height of the Bhutan pine, the team led by Guo Qinghua, director of the Institute of Remote Sensing and Geographic Information Systems at Peking University, used lidar technology for surveying and mapping.

" Lidar is an active remote sensing technology that can directly, quickly and accurately obtain the three-dimensional point cloud model of the research object ," said Guo Qinghua.

By measuring the position and distance of multiple points in space and processing these data with a computer, we can eventually build a 3D mapping data model of the area where the tree is located. In this way, it becomes very easy to accurately calculate the height of the tree.

When measuring the Yunnan Huangguo Fir, the drone was used to carry out multiple measurements. The drone was flown to the top of the tree crown, the rope was lowered, and the length of the rope was measured. The use of drones can ensure that the rope is vertically taut, which more accurately reflects the true height of the tree.

The significance of studying big trees

The two record-breaking trees discovered this time are of great value and significance for our study of plant physiology, especially the physiology of water and nutrient transport .

For example, the Bhutan pine discovered this time is 76.8 meters high, which is equivalent to a 25-story residential building. If there is no water pump to provide pressure, we can't enjoy tap water service at such a height. So how do trees without water pumps send water from the roots to the branches?

Initially, people believed that trees draw water through capillary action. The so-called capillary action means that water will "climb" upward along very thin pipes. The thinner the pipes, the higher the climbing height. However, after calculation, it was found that the capillary action generated by the size of the transport pipes (vascular bundles) of large trees is simply unable to deliver water to a height of dozens of meters.

In fact, big trees also have a "water pump" - the leaves at the top of the branches. The leaves continuously release water vapor into the air, so that the water in the vascular bundle of the trunk is replenished. Through this transfer, the water absorbed by the roots is "pumped up". Because it is related to transpiration, this special lifting force is called transpiration pull . However, how this water supply system operates all year round and why it produces such a huge pull is still a mystery.