Natures wonders: trees react to danger, communicate (Introduction)

by David Turell @, Tuesday, September 20, 2016, 05:29 (1255 days ago) @ David Turell

This article describes how trees react to danger and communicate, and much more:

"There's increasing evidence to show that trees are able to communicate with each other. More than that, trees can learn.
If that's true — and my experience as a forester convinces me it is — then they must be able to store and transmit information. 


"It sounds incredible, but when you discover how trees talk to each other, feel pain, nurture each other, even care for their close relatives and organise themselves into communities, it's hard to be sceptical.


"The other beeches around the stump had been pumping sugar into it for centuries to keep it alive, through their tangled roots.
Most individual trees of the same species growing in the same copse or stand will be connected through their root systems. It appears that helping neighbours in times of need is the rule, which leads to the conclusion that forests are super-organisms, much like ant colonies.

"But the support they give each other is not random. Research by Professor Massimo Maffei at the University of Turin shows trees can distinguish the roots of their own species from other plants, and even pick out their own relations from other trees. Some are so tightly connected at the roots that they even die together, like a devoted married couple.


"I have observed oak, fir and spruce stumps as well as beeches that have survived long after the tree was felled. But it's not just silent support that trees offer each other.
Dr Suzanne Simard of the University of British Columbia in Vancouver has discovered that they can also send warnings using chemical signals and electrical impulses through the fungal networks that stretch under the soil between sets of roots — networks known as the 'wood wide web'.
These fungi operate like fibre-optic internet cables. Their thin filaments penetrate the earth, weaving through it in almost unbelievable density. One teaspoon of forest soil contains many miles of these tendrils.
Over centuries, if left undisturbed, a single fungus can cover many square miles and create a network throughout an entire forest. Through these links, trees can send signals about insects, drought and other dangers.


"This might help to explain how swarms of insect pests are able to identify trees becoming weak. It's conceivable that some caterpillars and beetles tune in to the warnings flowing from tree to tree, then test which individuals are failing to pass on the message, by taking a bite of their leaves or bark.


"There's one more way that animals communicate, through sound. I was dubious at first that trees could deliberately make noises, but the latest scientific research is persuading me otherwise.
Dr Monica Gagliano from the University of Western Australia has been monitoring roots with highly sensitive apparatus, and believes they crackle at a frequency of 220 hertz, which the human ear hears as a low A note.
When this note was played back to seedlings, their roots tilted towards the sound. It appears they could hear it, and were responding.


"...think about how umbrella thorn acacias on the African savannah defend themselves against giraffes.
When they start picking at foliage, the acacias begin pumping foul-tasting toxins into the leaves to deter them. It happens in minutes, which for a tree is instantaneous. The giraffes get the message and move on.
But they don't go to the next acacia. They wander at least 100 yards before trying their luck again. The reason is astonishing. As they come under attack, the acacias give off a warning gas called ethylene that signals a crisis to neighbouring trees.
That triggers other acacias to dump toxins into their own leaves, as a defensive measure.
And the giraffes have learned that when one tree tastes bad, others in the vicinity will, too.

"The exception is when the wind picks up and only trees downwind detect the ethylene in the air, and react. Giraffes know it too, and head upwind.
Elms and pines use a different tactic. When an insect eats a leaf, electrical signals travel from the damaged area to the roots — just as human tissue sends pain signals along the nervous system.
It takes at least an hour for the roots to react and unleash the defences, by flowing bitter compounds into the leaf to send the attacker packing. But something even more amazing is also happening: the tree identifies the attacker by its saliva. Armed with this, the tree releases phero-mones to summon specific predators, to prey on the insects. For example, elms and pines call on parasitic wasps that lay their eggs inside leaf-eating caterpillars, condemning them to slow, painful deaths. Trees are prepared to wait for revenge."

Comment: I view these reactions as automatic and amazing. They require some biochemical planning, not as complex as speciation. I'm not sure if God helped or they learned to do it n their own.

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