The Hidden Life of Trees: Chapters 7 - 12

Please use this thread to discuss the above referenced chapters.

Chapter Seven, Forest Etiquette, touches on the causal elegance of evolution. Why are old trees beautiful? One reason is that to get old, a tree needs good shape. If it has bad shape, such as a bendy trunk, it is far more likely to either fall over in a storm or get cracks that allow fungus and other pests to enter and weaken it. So old trees tend to have tall straight trunks, highly symmetrical crowns and root systems, and vigorous health. Again, this is a moral lesson for humanity, that growing straight and true protects against damaging pathologies.

I had not thought of this parallel between trees and humanity, but it's definitely worth exploring especially since we currently have similar lifespans; few humans or trees live to be much over 100 years old...

Trees that don't follow the etiquette manual find themselves in trouble. For example, if a trunk is curved, it has difficulties even when it is just standing there. The enormous weight of the crown is not evenly divided over the diameter of the trunk but weighs more heavily on the wood on one side, To prevent the trunk from giving way, the tree must reinforce the wood in this area. This reinforcement shows up as particularly dark areas on the growth rings, which indicate places where the tree has laid down less air and more wood. p. 38

My wife is a physical therapist and thinks this could be a parallel to arthritis. A joint becomes inflamed, cartilage is worn down, bone growth is increased to compensate, which is less flexible and less lubricated, leading to reduced articulation and more pain. Consider a healthy joint as an ice rink after the Zamboni machine does its thing, smooth as glass. An arthritic joint is that same rink after a hard fought NHL hockey period, all hacked up. Compensating for that pain may change movements and cause problems in seemingly unrelated areas, leading to walking gaits and movements that may be uncomfortable to observe let alone experience.

The author mentions bent and forked trunks and ones damaged by snow or sliding hillsides. Consider there is not much trees can do in that condition other than attempt to straighten out future growth, but they may be at increased risk for damage in stressful conditions. Similarly for humans once structural physical problems manifest...

I am grateful several times every day that I am Temporarily Able Bodied and have so far have avoided these situations.

Chapter 8 - Tree School describes how trees appear to learn how to conserve water for dry spells. Trees on the leeward side of a large hill tend to fare much better during a period of drought than those on a windward side. Trees on the windward side are spoiled, they use lots of water and don't know how to conserve it while trees in drier areas are used to that and use water more sparingly. How do they learn this?

So let's return to the idea of school. If trees are capable of learning (and you can see they are just by observing them), then the question becomes: Where do they store what they have learned and how to they access that information? After all, they don't have brains to function as databases and manage processes. It's the same for all plants, and that's why some scientists are skeptical and why many of them banish to the realm of fantasy the idea of plants' ability to learn. p. 47

He describes this learning process as rather dramatic, not just experiencing thirst, but powerful stresses on the entire tree. Drying wood crackles and pops, 3 foot long tears open bark to fungus, and the tree attempts to repair this with pitch.

And with that, we have arrived at the heart of tree school. Unfortunately, this is a place where a certain amount of physical punishment is still the order of the day, for Nature is a strict teacher. If a tree does not pay attention and do what it's told, it will suffer. Splits in its wood, in its bark, in its extremely sensitive cambium (the life giving layer under the bark): it doesn't get any worse than this for a tree. It has to react, and it does this not only by attempting to seal the wound. From then on, it will also do a better job of rationing water instead of pumping whatever is available out of the ground as soon as spring hits without giving a second thought to waste. The tree takes the lesson to heart, and from then on it will stick with this new, thrifty behavior, even when the ground has plenty of moisture - after all, you never know! p. 44 - 45

He goes on to summarize a study of mimosas that recoil from raindrops, but then learn to ignore that harmless stimulus even weeks later. But he does not attempt to answer how plants store or access information. He ends this chapter with a bit of speculation.

When I think about the research results, in particular in conjunction with the crackling roots I mentioned earlier, it seems to me that these vibrations could indeed be much more than just vibrations - they could be cries for thirst. The trees might be screaming out a dire warning to their colleagues that water levels are running low. p.48

LanDroid wrote: ↑Sat Jun 17, 2023 7:04 pm trees appear to learn how to conserve water for dry spells.

This is a really interesting scientific finding that challenges concepts of consciousness.

It seems reasonable to argue that any organism that can learn is conscious.

If trees can learn, changing their behaviour in response to stimuli, and recalling that information later, it seems they have conscious awareness despite the absence of a nervous system.

This is an example of how life is far more complex than our current prevailing scientific assumptions have yet discovered.

Scientist Monica Gagliano writes on plant cognition. Chapter Eight cites an article about her work https://www.news.uwa.edu.au/archive/201 ... ories-too/ Move over elephants – plants have memories too, where she proves that mimosa can learn how to respond to rain. Here is the abstract of the journal article.

"The nervous system of animals serves the acquisition, memorization and recollection of information. Like animals, plants also acquire a huge amount of information from their environment, yet their capacity to memorize and organize learned behavioral responses has not been demonstrated. In Mimosa pudica-the sensitive plant-the defensive leaf-folding behaviour in response to repeated physical disturbance exhibits clear habituation, suggesting some elementary form of learning. Applying the theory and the analytical methods usually employed in animal learning research, we show that leaf-folding habituation is more pronounced and persistent for plants growing in energetically costly environments. Astonishingly, Mimosa can display the learned response even when left undisturbed in a more favourable environment for a month. This relatively long-lasting learned behavioural change as a result of previous experience matches the persistence of habituation effects observed in many animals."

That reminds me of a bit of a craze in the 1960's that started when someone hooked up electrodes to his houseplants to record any electrical signals generated. He's in another room and thinks about lighting a flame under a leaf of a certain plant to see what signals might be recorded. He does this, looks at the data, and realizes the plant's electrical signals spiked at the instant he first thought about burning the leaf. This led to bizarre theories hypotheses about plants reading minds. Obviously this did not catch on, but I wonder if the author will describe monitoring electrical signals.

LanDroid wrote: ↑Thu Jun 22, 2023 8:29 am the plant's electrical signals spiked at the instant he first thought about burning the leaf.

https://en.wikipedia.org/wiki/Plant_per ... aranormal) says The television show MythBusters concluded that the results of related experiments were not repeatable, and that the theory was not true.

https://en.wikipedia.org/wiki/The_Secret_Life_of_Plants says authorities are unable to accept that emotional plants "might originate in a supramaterial world of cosmic beings which, as fairies, elves, gnomes, sylphs, and a host of other creatures, were a matter of direct vision and experience to clairvoyants among the Celts and other sensitives. A review in The New Yorker says “The Secret Life of Plants,” by Peter Tompkins and Christopher Bird, presented a beguiling mashup of legitimate plant science, quack experiments, and mystical nature worship that captured the public imagination at a time when New Age thinking was seeping into the mainstream.

https://www.youtube.com/watch?v=pvBlSFVmoaw shows some electrical experiments with plants that count and communicate, including mimosa and Venus fly traps.

Plant consciousness is a topic that is widely condemned as absurd pseudoscience. The Hidden Life of Trees is careful to avoid such speculation. It does though push up against this boundary by framing scientific discovery in anthropomorphic terms such as learning. I like how it explains facts that many people would regard as fiction if they were not so well supported. A big cultural problem is that people bring strong prejudices to bear in assessing new claims. This book helps us to see that our assumptions can be proven wrong.

Chapter 10 The Mysteries of Moving Water
How does water make its way up from the soil into the tree's leaves?

Capillary Action? No, this accounts for a rise of water in the tree of 3 feet at most.
Transpiration? A mature beech tree can exhale 100s of gallons of water a day, but this suction is not enough to explain the situation.
Osmosis? No, this works only in the roots and leaves, not in the trunk.

So where does this leave us? We don't know.
...So many questions remain unanswered. Perhaps we are poorer for having lost a possible explanation or richer for having gained a mystery. But aren't both possibilities equally intriguing?

NO! These possibilities are NOT intriguing, they are embarrassing! We may understand the mathematics of the universe down to the first few trillionths of a second of the big bang, but we do not even know how water moves from soil to the tops of giant redwood trees??? Sorry, but our current knowledge of nature is dismal at best.

LanDroid wrote: ↑Tue Jul 04, 2023 10:22 pm ...but we do not even know how water moves from soil to the tops of giant redwood trees??? Sorry, but our current knowledge of nature is dismal at best.

I'm not yet on this chapter, but I cannot accept that we don't know the answer to this question. Tons of books and websites have this natural process explained in detail. Are you saying that Peter Wohlleben claims this is still a mystery?