In nature, plants tend to be more low-key, they nest in a corner to develop alone, and do not actively intersect with people, so few endangered plants can be as conspicuous as some endangered animals.
However, there are many rare plants in the world, including one in China, which is called "the only son of the earth", because once there was only one plant left in the world.
This plant is the Putuo Thrush, and its wild mother tree is one of the rarest plants in China and the world, and many institutions have done their best to save it.
The only son of the earth - Putuo Thrush, source: Beijing Daily
This wild mother tree has an exclusive management department, staff dedicated to daily maintenance and recording of it, its seeds are sent into space, and the world is watching its fruiting.
So the question is, why is there only one plant left of Putuo Thrush, and why do we spend so much effort to save it?
The discovery of the Putuo thrush
Like many plants, Putuo has always grown in Putuo Mountain, Zhoushan, but rarely attracts attention.
The various structures of Putuo Thrush, source: Shanghai Chenshan Botanical Garden
Around 1930, Chinese botanist Mr. Zhong Jiaojian discovered it during an inspection of plants along the coast of Zhejiang, and what caught Zhong's attention at that time was the flowers of Putuo Thrush, which is a dioecious, but there are obvious differences between male and female flowers, the female flowers are light red, and the male flowers are light yellow, which is very special.
This unique flower gave it the first written record, but it has not been determined to be a species.
Inflorescences, source: Shanghai Chenshan Botanical Garden
It was not until 1932 that another botanist, Professor Zheng Wanjun, identified it and determined for the first time that it was a species belonging to the genus Thrush in the birch family, and because it was only found in Putuo Mountain, it got the name Putuo Thrush.
However, so far, researchers are not very clear when Putuo thrush independently diverged.
Pictured: The only remaining wild Putuo thrush in Huiji Temple
In fact, when Putuo Goose Ear was first discovered, there were many such plants on Putuo Mountain, but at that time, people's attitude towards the new species was not as cherished as it is now, due to human damage to the ecology, as well as some problems with the species itself, and finally in just a few decades, it was only one left.
The only remaining plant grows in Putuo Mountain Huiji Temple, its height is about 14 meters, and the age of the tree is as high as 250 years old, so when people realize that it is a "unique seedling", it has actually shown signs of aging and cannot bear fruit every year.
In order to save this species, Chinese scientists have made great efforts, because the species itself is an "extinction constitution".
Putuo goose ear bud, source: Shanghai Chenshan Botanical Garden
The "extinct physique" of Putuo goose-ears
As a species, in fact, Putuo thrush is very easy to extinct, in the more commonly used words now, they have entered a dead end of evolution and cannot extricate themselves, and because of this, it accidentally left only one plant.
The first is their flowers. Putuo thrush begins to bloom in mid-to-early April every year, but the beginning of the blooming are male flowers, and the female flowers will open in mid-to-late April, and the average number of days that males and females can really meet is only 9 days, and the weather in Zhoushan in April is not good, and the 9-day window is easily broken by bad weather and cannot complete pollination.
What's even more bizarre is that their female flowers generally open in the highest places, while the male flowers bloom in the lower places, which makes it difficult to complete pollination by wind, and it becomes very difficult for them to complete pollination naturally due to the decline of ecologically destructive pollinators.
According to statistics, with artificial assistance, the seed emergence rate of Putuo Thrush can only reach about 2.5%, because most of the seeds are not pollinated.
Source: Shanghai Chenshan Botanical Garden
The second is their seeds. The seeds of Putuo Thrush have the characteristics of typical island plant seeds, that is, thick and hard shells, such as the coconuts we are familiar with.
This characteristic is mainly to cope with the troubled island climate, if the seeds are not wrapped well, it is difficult to survive, and such seeds are easier to complete in the seawater, not easy to rot.
Putuo thrush can certainly profit from their hard seeds, but this situation also certainly brings them a fatal drawback - that is, their seeds are difficult to germinate naturally, and may require enough rain (which I guessed) to soften the shell and complete the germination, in short, the germination conditions are very harsh.
Pollination is difficult, germination is difficult, and their reproductive capacity is unimaginably low, and it is believed that its offspring have never been found around the only remaining Putuo Thrush.
Therefore, after the slightest damage to the environment, they are rapidly on the verge of extinction.
How to save the "only child of the earth"?
In 1987, the alarm bell to save the species was listed by the International Species Conservation Commission (SSC) as one of the 12 most endangered plants in the world.
People began to protect and care for the sole survivors of this species, and to pay constant attention to its health. Under the care of special personnel, this "old" Putuo thrush gradually regained its vitality, and it began to bloom and bear fruit every year.
Researchers then spent decades studying its artificial pollination, reproductive techniques, and more. For Putuo Hornbeam, there are actually two ways to reproduce it - sowing and cuttings can be used, so with the unremitting efforts of researchers, the number of Putuo Hornbeam soon began to grow, reaching about 40,000 in 2015.
However, all 40,000 plants are descendants or clones of the only survivor of that plant, so it is only a large number and severely lacks genetic diversity, which makes it still vulnerable.
Therefore, the researchers have to screen out its mutants, which is very difficult, and the genetic information of each tree must be screened and tested, and the population size and cultivation environment must be continuously expanded.
The first sturdy photograph of Shanghai, source: Shanghai Chenshan Botanical Garden
By the end of 2018, the researchers sent it to 13 units in different regions of the country for ex situ preservation and cultivation, and the current results are that the Huozhou area in Shanxi can be cultivated outdoors, Zhengzhou can bloom and bear fruit, and Shanghai's Putuo thrush has successfully fruited this year (Shanghai has been cultivated for more than 10 years, but flowered last year but did not bear fruit).
Of course, it's not enough on Earth; when Tiangong-1 was launched in 2011, it was sent into space along with the seeds of three other critically endangered plants.
In fact, the purpose of sending some plant seeds into space is to hope to obtain their high-quality mutant individuals, so most crops have this "treatment".
However, for critically endangered species like the Putuo thrush, it is more about enriching their genetic diversity.
Finally: why save it?
Many people may ask, why do we go to such great lengths to save a plant that seems to be of little help to humans? Is it really worth it?
If this question were asked to people before, it might be hard to get an answer, maybe there would be some debate, or maybe more people would think it wasn't worth it.
But putting this question in the moment, its answer is obvious and worth it!
After entering the 21st century, natural disasters have become more and more "magical", locust plagues, hot weather, forest fires have set new records and cognition again and again, and people have become more and more aware of how important species diversity is to the earth's ecology.
Obviously, we are also part of the Earth's ecology and highly dependent on its balance, so saving a species also means saving ourselves.
Source: The Paper