Recently, extremely tall trees in China have been frequently discovered. The expedition team from the Institute of Botany of the Chinese Academy of Sciences found a tall yunnan Huangguo fir primary forest in Chayu County, Tibet, the tallest of which was 83.2 meters high, setting a new record for the tallest tree in China. This is the second discovery of the Tibetan Plateau scientific expedition "Forest and Shrub Ecosystems and Resource Management". Earlier, the Peking University team also found a 76.8-meter-high Bhutan pine tree in Metuo County, Tibet.
Today, we will talk about the biological knowledge behind these "highest trees".
The tallest trees grow deep in nature
The tallest tree in China previously found was a bald fir tree in Taiwan that is 81 to 82 meters tall. In October 2021, a 72-meter-tall bald fir in the Gaoligong Mountain Conservation Area in Yunnan Province, measured by the Wild China team, was the tallest tree previously measured in Chinese mainland.
Looking around the world, the height of the tallest tree is even higher.
In the late 19th century, the almond eucalyptus in mainland Australia was once considered the tallest tree in the world, and it is said that the tallest tree was discovered on the watt river in 1871, claiming to be 132.6 meters high, and the surveyor was an ordinary forestry worker, but this claim was not universally recognized. Discovered in 1881, a 114.3-meter-tall almond eucalyptus has also been awarded the title of the world's tallest tree.
The tallest tree in the world, which is now often mentioned, is the North American redwood. North American sequoia is produced off the coast of California, USA, and is a large tree that is commonly up to 100 meters high. In 2006, a 116-meter-tall North American redwood tree was discovered in the Redwood Grove National Park in the United States and was named "Hyperion God" by the staff. The god Hyperion is one of the twelve titan gods in Greek mythology, which originally meant "the one who crosses the sky".
In 2014, Boud and colleagues, a geographer at the University of Nottingham in the United Kingdom, conducted a flight mapping of the Dannong Valley Conservation Area in Sabah, Malaysia. In this survey they found a towering tree and named it "Menara", which means "tower" in Malaysian, which is a double tree of Wong Sha Lo. At the time, they didn't know the height of the tree. It was not until 2019 that accurate measurements were taken of the tree, confirming that the tree was 100.8 meters tall. Researchers believe that the "tower" may be the tallest tree in Asia at present.
The tallest trees in the world are mainly distributed in the Amazon forests of the United States, Malaysia, Brazil and other places, and the height of the trees is more than 100 meters. Including the tallest tree in China, these extremely tall trees grow in the depths of nature that have not been disturbed or affected by humans.
Growing tall is a need for survival competition
The research team that found the "tower" of the double tree "Pagoda" in Sabah, Malaysia, found through in-depth research that the weight of the "tower" was removed from the roots, reaching a height of 81.5 tons, which is equivalent to the weight of 13 African steppe elephants. Moreover, even if the tree grows to 255 meters, it can still support its own weight. Therefore, it will take a long time for the "tower" to be crushed by its own weight.
Moreover, there are other similarly tall trees in this part of Sabah, such as the 89.5-meter-high and 97-meter-high Huangluo double tree, and the 94.1-meter-high Sapra tree, plus the Dipterocarp family tree, and there are 50 local trees over 90 meters high.
The reason why the local tree grows so tall is first of all the need for survival competition, but also determined by the geographical location. Trees of the family Diplodontidae and other dipterocarp can grow so tall, partly to compete for sunlight, moisture, and nutrients, and on the other hand, to use the wind that blows across the top of the tree to spread their seeds so that their offspring can reproduce further. This principle is like a dandelion that wants to spread their seeds by the wind, so these tall trees can be seen as very large dandelions.
At the same time, there are so many tall trees in the area because of its geographical environment. Sabah is nicknamed the "Land of Winds", but Sabah is just outside the typhoon belt and is a buffer zone between strong winds and the northwestern region of Malaysia. Moreover, Sabah, unlike congo and the Amazon rainforest, is located on an island rather than an inland area, which means that the storms that Sapa suffers are less intense. Sabah is actually located in the leeward zone of the valley and has escaped the strong winds that blow through it, so the trees grow tall but are not blown by the strong winds.
The "Tree King" has an astonishing amount of carbon storage
Growing tall trees means being competitive, and if there are more tall trees and "tree kings" in a forest, it proves that the environmental ecosystem is productive. The so-called productivity of ecosystems refers to the total amount of organic matter or organisms produced per unit area or volume in a certain period of time, which can be expressed in quantity, weight or energy.
An ecosystem is highly productive, representing its ability to enrich carbon and has the potential to produce and sustain a large number of organisms, so that more tall trees can be bred. The place where the "tree king" can be bred is, of course, an environment with better original ecology and higher productivity.
Sabah in Malaysia is not only productive, but also has good groundwater resources. Similar to Sabah is the Amazon rainforest in Brazil. In 2019, brazilian researchers examined satellite imagery from Brazil's National Institute of Space Research and found a cluster of large trees 70 to 80 meters tall in the Amazon rainforest. Most of these large trees are located on the edge of the river, most of which are more than 70 meters high and belong to the Amazon bean (a type of sandalwood). Later, the scientific research team measured through field investigations that the tallest one was 88.5 meters high, and the age of this group of large trees was 400 to 600 years old. The trees are remote and avoid the route the hurricane crosses.
The existence of tall trees in the Amazon rainforest is a productivity in itself. The Amazon rainforest and other tropical forests store between 90 billion and 140 billion tonnes of carbon, helping to stabilize the world's climate. The huge size of tall trees can accumulate huge amounts of biomass and carbon storage. In general, the carbon storage of each large tree is equivalent to hundreds of ordinary trees, and the "tree king" is even more so, and the carbon storage of each large tree is as much as 1 hectare of forest (about 160 tons). The Amazon rainforest alone accounts for 1/10 of all biomass on Earth.
The results of the amazon institute, Brazil's national research institute, showed that a tree with a diameter of 10 meters emits more than 300 liters of water into the atmosphere every day in the form of a gas, more than twice the average daily water consumption of a Brazilian. Trees up to 70 meters tall emit dozens of times more water into the atmosphere every day than small trees below 10 meters. In addition, the Amazon rainforest provides 1/5 of the fresh water that flows into the world's oceans.
It is of great significance for the maintenance of biodiversity
Quite a few studies have shown that forests with higher tree growth have higher biodiversity. A research team in the United States studied more than 80,000 small plots of woodland in the United States, measured tree height and species composition per 600 square meters of land, and combined with data from nearly 1,000 square kilometers of grid land, concluded that the maximum height of trees was positively correlated with the diversity of tree species.
Researchers at the Chinese Academy of Forestry have found that tree height is an important factor affecting biodiversity, and the higher the tree, the more moss grows and adsorbs, the more conducive it is to the survival of other organisms. The reason is that the height of the tree restricts the small climate change of the entire vertical gradient from the canopy to the ground, and this small climate change can allow the epiphytic bryophytes of the tree to find different areas to adapt to their own survival, making the species more diverse.
Taking Metuo as an example, in the montane rainforest of 76.8 meters high Bhutan pine found in Metuo County, Tibet, there is also the densest 70-meter + giant tree community in China, which shows that tall trees and other tree species are mixed together to form a rich biodiversity of Metuo. The Brahmaputra Grand Canyon, which belongs to Metuo County, has a total length of 504.6 kilometers and a drop of more than 7,000 meters, which is one of the 34 biodiversity hotspots in the world. In terms of topography, there are highland meadows common in Tibet, mountains covered by tall fir trees in the subarctic zone, and rainforests overgrown with giant banana trees. Moreover, Metuo County has complex landforms, large differences in altitude, diverse habitat types, abundant heat, abundant rainfall, almost all vegetation types from tropical rainforests to alpine stony beaches, and has bred almost all terrestrial vegetation types from tropical to cold, and distributes 65% of the known higher plant species on the Qinghai-Tibet Plateau.
These rich plants and tall fir trees attract many animals and are home to many endangered animals such as the clouded leopard, snow leopard and impala, and are the only confirmed Bengal tiger habitat in China. Thanks to the biological resources of the forest, more new species have also been discovered in Metuo County and the Brahmaputra Grand Canyon. For example, in 2005, the newly discovered ink desurgent frog; the newly discovered ink deodorant frog in 2008; the new primate species - white-cheeked macaque monkey was newly discovered in 2015; the newly discovered spiny warty toad in 2016; the new genus and new species of mammals - the molting of the alpine mole genus in 2019; and the new discovery of The Zhou's horned toad and the Leaf horned toad in 2020.
In the newly released list of national key protected animals, there are nearly 30 species of national key protected animals recorded in Metuo. Among them, the Motuo mole lives in oak bushes at an altitude of 2400 to 3700 meters, and is only produced in the Gedang and Damu townships of Metuo.
This shows that forests with tall trees and multi-tree species are of great significance for the maintenance of biodiversity.
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How is the "height" of the tallest tree measured
The method of measuring the height of trees is both modern technology and primitive means.
For example, when measuring the tallest tree in Asia, the "Tower", the most primitive "tree climbing" method was used in 2019, and the local climber Jamie climbed to the top of this yellow tree and put the measuring ruler on the ground to confirm that the height of the tree was 100.8 meters. In October 2021, the Wild China team measured 72 meters of bald fir in the Gaoligong Mountain Conservation Area in Yunnan, also using the "tree climbing" method.
The measurement of the height of 83.2 beige fruit fir and 76.8 meters of Bhutan pine used backpack lidar and drone methods. The lidar method is to use lasers to determine the distance between two points; the drone method is to use a drone to fly to a flat place at the top of the canopy, lower the rope, and then measure the length of the rope. (Zhang Tiankan)
Source: Beijing Daily