How does a tree move

Trees that can walk up to 20m per year


Nature & Outdoors

Trees that can walk up to 20m per year

(Image credit: Andrew Linscott/Alamy)

By Karl Gruber16th December 2015

Like the Ents from JRR Tolkien’s epic Lord of the Rings saga, these trees actually move. But can they walk fast enough to escape the chainsaw and machetes that threaten them?

A biodiversity hotspot

Some spots of the Sumaco Biosphere Reserve host nearly 500 species of birds, 51 species of large mammals, 64 species of reptiles, 61 species of amphibians, 6,000 plant species, more than 600 species of butterflies and several very old fern trees, some hundreds of years old.

It takes a whole day to travel from Ecuador’s capital, Quito, to the heart of the Unesco Sumaco Biosphere Reserve, some 100km to the southeast. The journey entails three hours by car to the edge of the forest, and then anywhere from seven to 15 hours by boat, mule and foot, mostly uphill and on a muddy road, to reach the interior. But the effort is worth it, considering you wind up in the middle of a pristine forest that houses a rather unusual find: walking palm trees.

Like the Ents from JRR Tolkien’s epic Lord of the Rings saga (only a bit slower), these trees actually move across the forest as the growth of new roots gradually relocates them, sometimes two or three centimetres per day. While some scientists debate whether these trees walk, Peter Vrsansky, a palaeobiologist from the Earth Science Institute of the Slovak Academy of Sciences Bratisla, claims to have seen this phenomenon first hand.

“As the soil erodes, the tree grows new, long roots that find new and more solid ground, sometimes up to 20m,” said Vrsansky. “Then, slowly, as the roots settle in the new soil and the tree bends patiently toward the new roots, the old roots slowly lift into the air. The whole process for the tree to relocate to a new place with better sunlight and more solid ground can take a couple of years.”

These mysterious trees remind visitors of Tolkien's creations (Credit: Peter Vrsansky)

Vrsansky, a local guide and conservationist Thierry García have spent the last few months living in the forest while documenting the threats that jeopardize some of its biological wonders.

“During our investigations, we discovered some undocumented 30m waterfalls, two new vertebrate species (a lizard and a frog) and we were attacked by a big herd of really big woolly monkeys,” Vrsansky said. “They were throwing everything at us, including 6m-long dry branches, even their faeces and urine.”

The experience has been daunting as they forage from the forest and survive arduous conditions; Vrsansky recalls losing about 10kg of weight within a week. But despite the hardships, Vrsansky said he was exhilarated when he found, in a single spot, more than 150 cockroach species – more than those currently living in all of Europe. These cockroaches were nothing like the hideous critters lurking around your house; they were all different colours, many either luminescent, shining in the dark, or impossible to discriminate from their backgrounds due to their ability camouflage themselves by mimicking leafs.

(Credit: Peter Vrsansky)

(Credit: Thierry Garcia)

(Credit: FLPA/Alamy)

(Credit: Peter Vrsansky)

(Credit: Jason Edwards/Alamy)

(Credit: Andrew Linscott/Alamy)

Surprisingly, this fairy-tale forest is currently for sale through the “agricultural reform”, which supports locals cutting down trees in order to gain living rights to a piece of land. “What is happening is that people come, cut down a bunch of trees and gain ownership of their piece of land. Then, after five years, as stipulated by this new law, they are able to sell the land. And they do,” Vrsansky said.

Until now, few locals have technically lived inside the forest. A local shaman claims there is a “bad spirit” inside some parts of the reserve, and the forest is rich in disease-bearing insects and other potential threats.

Deforestation poses the biggest threat to Ecuador's wildlife (Credit: James Morgan/Alamy)

Still, buying the reserve piece by piece is one of the strategies conservationists are using to save it from deforestation. One hectare goes for less than $500, and so far, García has bought more than 300. “He is not rich,” Vrsansky said of the conservationist, “But now he owns and protects his own harpy eagle, his own jaguar and more than 10,000 arthropod species. And sorry, I forgot, his own waterfall.”

Other potential conservation strategies include selling the land to a university or institute so it becomes a protected research area, or using the forest to promote tourism.

“For [visitors], walking by condors and raging volcanoes, combined with the pristine forest, is a window to an existential past,” Vrsansky said. “The forest itself? This is a full display of the life on Earth. You literally feel [like you’re] diving inside an ocean full of life.”

At 3,500m, the active Reventador volcano erupts – at night, you can see lava and melted rocks thrown with huge power (Credit: Jeff Cundith)

Since 2010, about 200 hectares of forest have been cleared near the Bigal River Biological Reserve, a French-supported research station within the Sumaco reserve. Elsewhere in the reserve, many thousands of hectares have been affected since the building of an access road in 1986.

“This [cutting] is a shame, as Ecuador is one of the world countries with the highest partition of protected areas. But the trees can’t walk fast enough to escape the chainsaw and the machetes backed by current legislation,” Vrsansky said.

San Rafael Falls, Ecuador's tallest waterfall, in the Sumaco Biosphere Reserve (Credit: Kseniya Ragozina/Alamy)

CLARIFICATION: A previous version of this story did not state that some scientists dispute the claim of walking trees. The story has been updated.

FOLLOW-UP: How do trees carry water from the soil around their roots to the leaves at the top? Clearly, they are fighting gravity--so how do they do it?

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Last week we presented a general outline of how trees lift water. Donald J. Merhaut of Monrovia Nursery Company, headquartered in Azusa, Calif., has provided a more detailed reply:

"Water is often the most limiting factor to plant growth. Therefore, plants have developed an effective system to absorb, translocate, store and utilize water. To understand water transport in plants, one first needs to understand the plants' plumbing. Plants contain a vast network of conduits, which consists of xylem and phloem tissues. This pathway of water and nutrient transport can be compared with the vascular system that transports blood throughout the human body. Like the vascular system in people, the xylem and phloem tissues extend throughout the plant. These conducting tissues start in the roots and transect up through the trunks of trees, branching off into the branches and then branching even further into every leaf.

"The phloem tissue is made of living elongated cells that are connected to one another. Phloem tissue is responsible for translocating nutrients and sugars (carbohydrates), which are produced by the leaves, to areas of the plant that are metabolically active (requiring sugars for energy and growth). The xylem is also composed of elongated cells. Once the cells are formed, they die. But the cell walls still remain intact, and serve as an excellent pipeline to transport water from the roots to the leaves. A single tree will have many xylem tissues, or elements, extending up through the tree. Each typical xylem vessel may only be several microns in diameter.

"The physiology of water uptake and transport is not so complex either. The main driving force of water uptake and transport into a plant is transpiration of water from leaves. Transpiration is the process of water evaporation through specialized openings in the leaves, called stomates. The evaporation creates a negative water vapor pressure develops in the surrounding cells of the leaf. Once this happens, water is pulled into the leaf from the vascular tissue, the xylem, to replace the water that has transpired from the leaf. This pulling of water, or tension, that occurs in the xylem of the leaf, will extend all the way down through the rest of the xylem column of the tree and into the xylem of the roots due to the cohesive forces holding together the water molecules along the sides of the xylem tubing. (Remember, the xylem is a continuous water column that extends from the leaf to the roots.) Finally, the negative water pressure that occurs in the roots will result in an increase of water uptake from the soil.

"Now if transpiration from the leaf decreases, as usually occurs at night or during cloudy weather, the drop in water pressure in the leaf will not be as great, and so there will be a lower demand for water (less tension) placed on the xylem. The loss of water from a leaf (negative water pressure, or a vacuum) is comparable to placing suction to the end of a straw. If the vacuum or suction thus created is great enough, water will rise up through the straw. If you had a very large diameter straw, you would need more suction to lift the water. Likewise, if you had a very narrow straw, less suction would be required. This correlation occurs as a result of the cohesive nature of water along the sides of the straw (the sides of the xylem). Because of the narrow diameter of the xylem tubing, the degree of water tension, (vacuum) required to drive water up through the xylem can be easily attained through normal transpiration rates that often occur in leaves."

Alan Dickman is curriculum director in the biology department at the University of Oregon in Eugene. He offers the following answer to this oft-asked question:

"Once inside the cells of the root, water enters into a system of interconnected cells that make up the wood of the tree and extend from the roots through the stem and branches and into the leaves. The scientific name for wood tissue is xylem; it consists of a few different kinds of cells. The cells that conduct water (along with dissolved mineral nutrients) are long and narrow and are no longer alive when they function in water transport. Some of them have open holes at their tops and bottoms and are stacked more or less like concrete sewer pipes. Other cells taper at their ends and have no complete holes. All have pits in their cell walls, however, through which water can pass. Water moves from one cell to the next when there is a pressure difference between the two.

"Because these cells are dead, they cannot be actively involved in pumping water. It might seem possible that living cells in the roots could generate high pressure in the root cells, and to a limited extent this process does occur. But common experience tells us that water within the wood is not under positive pressure--in fact, it is under negative pressure, or suction. To convince yourself of this, consider what happens when a tree is cut or when a hole is drilled into the stem. If there were positive pressure in the stem, you would expect a stream of water to come out, which rarely happens.

"In reality, the suction that exists within the water-conducting cells arises from the evaporation of water molecules from the leaves. Each water molecule has both positive and negative electrically charged parts. As a result, water molecules tend to stick to one another; that adhesion is why water forms rounded droplets on a smooth surface and does not spread out into a completely flat film. As one water molecule evaporates through a pore in a leaf, it exerts a small pull on adjacent water molecules, reducing the pressure in the water-conducting cells of the leaf and drawing water from adjacent cells. This chain of water molecules extends all the way from the leaves down to the roots and even extends out from the roots into the soil. So the simple answer to the question about what propels water from the roots to the leaves is that the sun's energy does it: heat from the sun causes the water to evaporate, setting the water chain in motion. "

How to cut down a tree: a step by step process | Articles

June 03, 2019

Among arborists, tree removal is considered a specialty. The dismantling technique requires special experience, in-depth knowledge, the ability to work in a team of two people and the use of the right equipment. To better understand this profession, colleagues from Petzl went to a job site in the south of France. There they met Laurent Pierron, an arborist, who showed the process step by step.

Attention! This article is not intended to be a comprehensive tree removal guide. It only describes in general terms the process of dismantling trees and is not a training material.

When should a tree be cut in pieces?

Sometimes it is not possible to simply cut down a tree because of the location in which it is located. For example, in a city where a tree fall poses too much risk. This also applies to our current task, on the territory of the city of Valence (France). The only solution is to carefully disassemble the tree, cutting it into pieces from top to bottom.

Job site preparation

Any job site where tree work is planned (whether pruning or any other type of work) has a work plan in advance. This includes risk assessment, tree condition assessment, understanding environmental constraints, determining how to handle waste, preparing a list of equipment, determining the number of workers required, preparing signage for the security perimeter.

Choosing the right weather window

Tree work requires ideal weather conditions. A tree is a living thing that moves, and an arborist climbing a tree must work in a moving environment. Strong winds or rain can turn any job into a daunting task. If, for example, a thunderstorm warning comes in, the job site is immediately closed.

The main steps in the process of dismantling a tree

  • Access to the top of the tree in the traditional way: passing the cord, setting the rope, then climbing.
  • Set up a station at the top of a tree. The arborist, at his workstation, sets up a system of pulleys to control the speed and direction of the descent of the tree sections all the way to the ground. At this stage, the person at the base of the tree also prepares the necessary equipment: prepares traction and guiding ropes, a chainsaw, etc.
  • All tree branches are cut from the base to the top. Once the necessary systems are in place on the tree and on the ground, work can begin to dismantle the tree. The lower branches are always cut first. Then the arborist moves higher to the next branches. This method allows all branches to reach the ground without any obstruction.
  • The trunk can be sawn in pieces. Once all the branches are cut, the trunk is sawn in parts, starting from the top. The length of each part is calculated taking into account the diameter and weight.

Worker safety

  • The arborist uses a work positioning system with a heavy-duty adjustable lanyard. The Petzl MICROFLIP, designed for tree work, consists of a rope with a metal core and a clamp. Use an additional choke to keep the sling snug against the tree trunk. Such a system will stop the fall in the event of a fall.
  • A second system is installed below the positioning lanyard using a ZIGZAG mechanical prusik. This gear serves both as a backup belay system and as a tree descent line.
  • Additional stability is provided by special spikes (gaffs). Please note that spikes are only used when removing trees.

Carrying a chainsaw

A chainsaw often weighs more than 8 kg. This must be taken into account when assessing physical activity when dismantling a tree. It is much more comfortable when the load is partially distributed on the shoulders, and not just on the belt. The shoulder straps for the SEQUOIA SRT do an excellent job of redistributing the load.

Pulley system: the most dangerous moment

Power pulleys must be used for the controlled lowering of tree trunk parts. The rope is attached to the center of the part of the trunk that needs to be lowered. This rope passes through a roller attached to an anchor point in a tree or troll. At the base of the tree, a special descender (Portawrap) is installed, with which the descent of parts of the tree is controlled. An important part of the preparation is determining the number of turns to wrap around the device. This is the most difficult stage. To determine the required number of turns, depending on the size of the descent section, you need a lot of experience in such work. Part of the trunk must be stopped before it hits the ground, but not too abruptly so that the tug does not throw the arborist out of the tree. When carrying out these works, the arborist and his assistant on the ground must coordinate their actions well. A person who works with a descender below cannot always see what is happening above and cannot estimate the loads himself. Therefore, accurate provision of information from above is important. Given the constant noise from chainsaws and shredders, it's easier to use walkie-talkies than to yell from treetop to the ground.

what language do they speak and how are they similar to people — T&P

Trees appeared on Earth before humans, but they are not accepted to be perceived as living beings. In his book The Secret Life of Trees: The Astounding Science of What Trees Feel and How They Interact, German forester Peter Wolleben tells how he noticed that trees communicate with each other, transmit information through smell, taste and electrical impulses, and how he himself learned to recognize their silent language. T&P translated the review of the book, which was published on the BrainPickings website.

The Hidden Life of Trees

When Volleben first started working with forests in the Eifel mountains in Germany, he had a very different idea of ​​trees. He prepared the forest for lumber production and "knew as much about the hidden life of trees as a butcher knows about the emotional life of animals. " He saw what happened when something alive, be it a creature or a work of art, became a commodity—the "commercial focus" of the work distorted his view of the trees.

But about 20 years ago everything changed. Volleben then began to organize special forest survival tours, during which tourists lived in log huts. They showed sincere admiration for the "magic" of trees. This kindled his own curiosity and love for nature, even from childhood, flared up with renewed vigor. Around the same time, scientists began to conduct research in his forest. Having stopped looking at trees as a currency, he saw in them priceless living creatures.

He says:

“The life of a forester is exciting again. Every day in the forest was a day of discovery. This led me to unusual methods of forest management. When you know that trees are in pain and have memory, and that their parents live with their children, you can no longer just cut them down, cut them off with your car.”

Revelation came to him in flashes, especially during regular walks in that part of the forest where the old beech tree grew. One day, passing by a pile of moss-covered stones that he had seen many times before, Volleben suddenly realized how peculiar they were. Leaning down, he made a startling discovery:

“The stones were of an unusual shape, as if curved around something. I carefully lifted the moss on one stone and found the bark of a tree. That is, it was not stones at all - it was an old tree. I was surprised how hard the "stone" was - usually in wet soil, a beech tree decomposes in a few years. But what struck me most was that I couldn't lift it. It seemed to be attached to the ground. I took out my pocket knife and carefully cut off the bark until I got to the greenish layer. Green? This color is found only in chlorophyll, which makes the leaves grow green; reserves of chlorophyll are also found in the trunks of living trees. It could only mean one thing: that piece of wood was still alive! Suddenly, I noticed that the remaining "stones" lay in a certain way: they formed a circle with a diameter of 5 feet. That is, I stumbled upon the twisted remains of a huge ancient stump. The interior has long since completely rotted away - a clear indication that the tree must have collapsed at least 400 or 500 years ago."

How could a tree cut down centuries ago still live? Without leaves, a tree cannot carry out photosynthesis, that is, it cannot turn sunlight into nutrients. This ancient tree received them in some other way - and for hundreds of years!

Scientists have solved the mystery. They found that neighboring trees help others through the root system, either directly, by intertwining the roots, or indirectly - they create a kind of mycelium around the roots, which serves as a kind of extended nervous system, connecting far-standing trees. In addition, trees at the same time show the ability to distinguish between the roots of trees of other species.

Wohlleben compared this smart system to what happens in human society:

“Why are trees such social creatures? Why do they share food with members of their own species, and sometimes even go further to feed rivals? The reason is the same as in the human community: being together is an advantage. A tree is not a forest. The tree cannot determine its local climate - it is at the disposal of the wind and weather. But together, trees form an ecosystem that regulates heat and cold, retains a large supply of water, and generates moisture. In such conditions, trees can live for a very long time. If each tree cared only about itself, some of them would never live to an advanced age. Then, in a storm, it would be easier for the wind to get inside the forest and damage many trees. The sun's rays would reach the earth's cover and dry it out. As a result, every tree would suffer.

So every tree counts for the community, and it's better for everyone to prolong life as much as possible. Therefore, even the sick, until they recover, are supported and fed by the rest. Another time, perhaps everything will change, and the tree that now supports others will need help. […]

A tree can only be as strong as the forest around it.”

One might ask if trees are not better equipped to help each other than we are, because our lives are measured in different time scales. Can our inability to see the full picture of mutual support in the human community be explained by biological myopia? Maybe organisms whose life is measured on other scales are better suited to exist in this grandiose universe where everything is deeply interconnected?

No doubt even trees support each other to varying degrees. Volleben explains:

“Every tree is a member of a community, but it has different levels. For example, most stumps start to rot and disappear in a couple of hundred years (which is not much for a tree). And only a few remain alive for centuries. What is the difference? Do trees have a "second class" population, like in human society? Apparently, yes, but the concept of "grade" does not quite fit. It is rather the degree of connection - or perhaps affection - that determines how willing the tree's neighbors are to help."

These relationships can also be seen in the tops of trees if you look closely:

“An ordinary tree stretches its branches until they reach the branches of a neighboring tree of the same height. The branches do not grow further, because otherwise they will not have enough air and light. You may get the impression that they are pushing each other. But a couple of "comrades" do not. The trees do not want to take anything away from each other, they stretch their branches to the edges of each other's crown and in the direction of those who are not their "friends". Such partners are often so closely related at the roots that they sometimes die together.”

© DCorn / iStock

But trees don't interact with each other outside of an ecosystem. They often turn out to be associated with representatives of other species. Wohlleben describes their olfactory warning system as follows:

“Four decades ago, scientists noticed that giraffes in the African savannah fed on the umbrella thorny acacia. And the trees didn't like it. In a few minutes, acacias began to secrete a toxic substance into the leaves in order to get rid of herbivores. The giraffes understood this and moved on to other trees nearby. But not to the closest ones - in search of food, they retreated about 100 yards.

The reason for this is amazing. Acacias, when eaten by giraffes, released a special "alarm gas", which was a signal of danger to neighbors of the same species. Those, in turn, also began to release a toxic substance into the foliage in order to prepare for the meeting. The giraffes were already aware of this game and retreated to that part of the savanna where it was possible to find trees to which the news had not yet reached.[…]”.

Since the age of a tree is much longer than a human, everything happens much more slowly with them. Volleben writes:

“Beeches, firs and oaks feel pain as soon as someone starts to gnaw on them. When a caterpillar bites off a piece of leaf, the tissue around the damaged area changes. In addition, leaf tissue sends out electrical signals, just like human tissue if it hurts. But the signal doesn't travel in milliseconds like a human's - it moves much more slowly, at a speed of a third of an inch per minute. So it will take an hour or more until the protective substances are delivered to the leaves to poison the pest's food. Trees live their lives very slowly, even if they are in danger. But this does not mean that the tree is not aware of what is happening with its different parts. For example, if something threatens the roots, the information spreads through the entire tree, and the leaves send odorous substances in response. And not some old ones, but special components that they immediately develop for this purpose.

The positive side of such slowness is that there is no need to raise a general alarm. The speed is compensated by the accuracy of the applied signals. In addition to smell, trees also use taste: each species produces a certain kind of "saliva" that can also be loaded with pheromones aimed at scaring away predators.

To show the important role trees play in the Earth's ecosystem, Volleben told a story that took place in Yellowstone National Park, the world's first national park.

Learn more