I've never seen anything like this before! It weighed 6,000 tons and lived for tens of thousands of years! But in the end it was slowly eaten...

Expert of this article: Li Ting, Master of Plant Protection, member of China Science Writers Association

Reviewer of this article: Shi Jun, researcher of botany, member of the Science Communication Working Committee of the Chinese Society of Botany

Plants can be found everywhere on Earth, and we have an inextricable relationship with them.

When you think of plants, what is the first thing that comes to your mind?

The straight and shady willow trees on both sides of the road, or the small green plants that beautify the office and home environment?

Today (June 5) is World Environment Day, and we would like to introduce three plants:

The first is the largest tree in the world - Pando Poplar Forest

The second one is the very common ginkgo

The third one is a thumb-sized "dwarf" water lily

But did you know that these beautiful plants are slowly disappearing? Don’t wait until they become extinct before we rediscover them in an apologetic way.

01

This tree, which has lived for tens of thousands of years and weighs 6,000 tons, is being slowly eaten

In Utah, USA, there is the world's largest tree - the Pando quaking aspen forest, which is known as one of the 40 wonders of the United States.

This tree is different from other trees. It is not a single individual, but a trembling aspen forest. All the trees in it are asexually reproduced from a male trembling aspen. The roots of these trees are all intertwined, stretching over 43.6 hectares, with more than 47,000 trunks, forming a huge trembling aspen forest.

Because all the roots are connected and come from the same ancestor, each tree is genetically identical, so from a biological point of view the entire quaking aspen forest is just one tree.

According to research, the Pando trembling aspen forest has survived for 14,000 years and weighs about 6,000 tons. No tree can compare with it so far. From this perspective, the Pando trembling aspen forest is the largest and longest-lived tree on earth.

The Pando Aspen Forest is a natural wonder that has built a rich ecosystem within its own forest. Despite various efforts to protect it, its size is still shrinking:

Imbalance of the forest ecosystem

As the world develops, human activities such as cutting down trees, occupying forest land and hunting animals are increasing. Some carnivores that are afraid of humans are forced to migrate, and the rest are also hunted by humans. Without the threat of carnivores, the number of herbivores increases rapidly, resulting in the imbalance between the number of carnivores and herbivores.

However, due to the excessive number of herbivores, the limited vegetation in the Panduo Poplar Forest was simply unable to meet their needs, so many newly grown young saplings were quickly eaten, resulting in the Panduo Poplar Forest being almost unable to grow new trees, and the inheritance within the forest was cut off.

Poor disease resistance

All the trees in the Pando Aspen Forest are asexually reproduced from a single male trembling aspen. For a long time, the other trees in the forest have largely maintained the same disease resistance as this mother male trembling aspen. It is difficult for these trees to change their disease resistance in line with environmental changes. Some plant diseases become more harmful after mutation, and they continue to invade the Pando Aspen Forest, causing the trees to gradually wither and die.

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Complex climate change

The Pando trembling poplar forest existed 14,000 years ago, during the last ice age on Earth, when temperatures were extremely low and the environment was freezing.

The Panduo trembling poplar forest grew and prospered in this cold climate and had long since adapted to the cold climate environment at that time.

However, due to the rapid development of industry, a large amount of harmful gases such as carbon dioxide are emitted, resulting in complex climate such as global warming. The Pando trembling poplar forest, which has adapted to cold weather for a long time, will find it difficult to adapt to this complex climate, causing many trees to be unable to continue to grow and gradually age and die.

02

Why is the ginkgo tree, which is so common, said to be endangered?

From the perspective of biological classification, based on evolutionary relationships, many organisms are related in the process of deduction, and there will be species of the same class or order.

However, in the biological classification of the order, family, genus and species, there is only one category of Ginkgo, and it has no genetic relationship with other plants, so it is a "unique" plant.

If humans fail to protect ginkgo and it becomes extinct, there will be no other plant on Earth that can replace it. Therefore, ginkgo is extremely scarce.

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In addition, the criteria for judging endangered plants cannot be based solely on the number of species that exist, but also on the genetic diversity of the species and the distribution of wild populations.

Although ginkgo trees are very common, most of them are cultivated by humans through asexual reproduction, such as cuttings and division. Ginkgo trees propagated asexually largely retain the genes and traits of the mother, and the genes and traits of their offspring have not changed. Therefore, from an overall perspective, there is still only one ginkgo tree.

Many scientists have been searching for ginkgo all over the world for a long time, but have rarely found the existence of wild ginkgo populations. This shows that the genetic diversity of ginkgo may have been on the road to extinction. Therefore, ginkgo has become an endangered species and urgently needs human protection.

03

The thumb-sized "dwarf" water lily is also struggling on the brink of extinction

The "dwarf" water lily is also called the Rwandan water lily. Originally, this species only grew in a hot spring in a valley in Rwanda, Africa, so it is also called the "hot spring water lily."

In 1987, a German plant scientist accidentally discovered this new water lily species while conducting a plant research mission in the area.

The Rwandan water lily is the smallest water lily in the world. The shortest diameter of its leaves is only 1 cm, and the flowers are so small that they can even be placed on the fingertips. The Victoria amazonica, which is also a water lily, has the longest leaves with a diameter of more than 3 meters. In comparison, the Rwandan water lily appears very petite.

Weibo screenshot

Unlike other water lilies, the Rwanda water lily prefers to grow in moist areas with plenty of water but also with soil. It is also the only water lily known to grow in soil. Its flowers are white, and its stamens are yellow. They stand upright several centimeters above the leaves, giving it a noble aura that can be admired from a distance but not touched.

However, in 2000, local residents in Rwanda cut off the water source for the growth of Rwandan water lilies in an unplanned manner for agricultural irrigation, resulting in the gradual depletion of the water source in the only habitat that can grow Rwandan water lilies. Without water, many wild Rwandan water lilies died, leaving no wild species of Rwandan water lilies.

Therefore, the IUCN Red List lists the species as extinct in the wild. Fortunately, before it became extinct, scientists had already realized the seriousness of the problem and collected multiple samples for artificial cultivation.

However, its reproduction has not been smooth. Many scientists have made countless attempts. Finally, by changing the gas concentration in the water to cultivate it, they finally saved the Rwandan water lily from the brink of extinction.

Pando trembling aspen forest, ginkgo and Rwanda water lily

It's just a microcosm of what we see.

There are still many natural treasures on earth

They are leaving us because of the destruction of the ecological environment.

Some have even become extinct

Protect the environment and coexist harmoniously with nature

Start with you and me

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