We have known for many years that trees communicate with each other, that their responses to insect and/or animal attack can be picked up by other trees. We know that the attacked tree can send out warning signals to other trees and these signals can be very specific; e.g. they can differentiate between leaf eating and sap sucking, and between insect and animal attack. The mechanics behind this are surprisingly straight forward and work well in a forest situation. This form of response communication is also surprisingly fast. Grazing animals have been observed lunching on every other tree and not chewing from one tree to the next; the theory being that by the time the animal has finished chomping on one tree the neighbouring tree knows what is coming and has already pumped its leaves full with less tasty substances.

We know that trees help each other. Nutrient sharing takes place, mainly between trees of the same species but inter-species help is also not uncommon. It would be nice to think that trees are caring beings and look after their neighbours because of some sense of ‘natural goodness’; but we suspect that is not the case. Nutrient sharing also typically takes place in a forest situation. The theory being that a forest functions as a ‘super organism’, a single living entity that just happens to be made up of thousands if not millions of separate living things. By helping your neighbours, you help yourself – the forest canopy stays intact, pests and diseases don’t get a chance to establish and the super organism remains strong.

The odd thing about nutrient sharing is that it seems to be controlled by fungus (the mycorrhizal fungi living on or in the roots), which poses the question; who or what is in really in control of the super organism? The other interesting thing about nutrient sharing is that it doesn’t seem to happen as much in planted/commercial forestry or in agricultural cropping situations. One theory there is that the addition of fertiliser (particularly phosphates) kills off the naturally occurring soil flora.

So, we know that trees communicate with each other [in a forest situation at least]. We know how this happens and we can guess why – but these forms of communication don’t involve sound, so we can’t really call it talking and it would be a stretch to call it a form of non-verbal communication as well.

But what if trees could make sound, and what if they could respond to the sounds other trees made? Could we consider that to be talking?

Well, trees do make sounds, not just sounds generated by wind passing through their branches or their leaves, but sounds generated from within. Tree sounds come from water and presumably tiny air bubbles moving through the plant with healthy trees making more sound than unhealthy trees.

Sound travels in waves and we detect these sound waves as vibrations, more sound equals more vibrations. Tree sounds come from water moving through the plant with most of the water entering the plant through the roots. The more actively roots are taking and moving water the greater that sound will be.

Now, here for the interesting bit… it seems that roots are attracted to the sounds/vibrations of other roots. A single root in the soil may not generate much sound but a bunch of roots actively moving water all at the same place will. There is a theory that roots can sense vibrations and will grow towards the source of the sound, i.e. there must be something good in the soil to generate so much sound so other roots want to join the party.

Trees are communal creatures they share information above ground, they share information below ground, they give each other shelter and share nutrients – in a forest or when part of a ‘super organism’ at least.

I have always said that trees don’t think, they respond and I’m not suggesting that these forms of communication are conscious actions or even unconscious processes, because trees don’t have consciousness; but with all of this communication going on, and at so many different levels what is it, if it is not some form consciousness?