A couple of years ago I wrote in the abstract about ‘Slow thoughts from a planet sized brain‘ [on March 25th, 2020]. I read on vacation in Suzanne Simard‘s book, ‘Finding the Mother Tree‘ that glutamate, which is the most abundant neurotransmitter in the human brain, is also transmitted through mycorrhizal networks connecting trees in forests. Mycorrhizal fungi live in the soil around the roots of plants in a symbiotic relationship with the plants transmitting water to, and receiving sugar from, the plant roots. Fir trees have been shown to transmit information about threats, e.g., budworm infestations, to one another and to other species of tree. The speed of this information transmission is fast enough that production of enzymes to protect the trees increases within a day of the appearance of the threat. We have assumed that folklore tales about enchanted forests are products of our imagination; but perhaps they are based on a long-lost appreciation that forests possess a level of consciousness. Consciousness seems to require different parts of a system to communicate with one another and form networks [see ‘Digital hive mind‘ on November 30th, 2016], which Simard and others have demonstrated occurs in forests with the mycorrhizal networks being equivalent to the neural network in our brains. The scale of a forest’s network is such that communication will be slower than in our brain but that is not necessarily an inhibitor of consciousness. So, perhaps forest-sized brains would be intermediate between human-sized and planet-sized.
Last month I mentioned that I started reading ‘Overstory’ by Richard Powers on my trip back from the US [see ‘When an upgrading is downgrading‘ on August 21st, 2019]. I only finished it about ten days ago because I have not had much time to read and it is a long book at 629 pages. It is a well-written book including some quotable passages, but one that I particularly liked which seems relevant in this era of polarised perspectives: ‘The best arguments in the world won’t change a person’s mind. The only thing that can is a good story.’ And, Richard Powers tells a good story about the destruction of the ecosystem, on which we are dependent, as a result of large-scale felling of ancient forests. The emphasis should be on ‘ancient’ because time for trees appears to run at a different speed than for humans. While we can observe the seasonal changes in an ancient woodland, we are barely conscious on the growth and movement of the woodland. When we read Shakespeare’s lines in Macbeth about ‘Great Birnam wood to high Dunsinane Hill shall come’, we think of it moving over the landscape at the speed of an army of people, whereas woods move so slowly that we do not live long enough to notice the change. For instance, there is a spruce tree in Sweden that is 9,500 years old. Our spatial understanding of a tree also leads to a misconception because we can only see the overstory, i.e. what is happening above ground; so, we think that each trunk is an individual tree, whereas for many types of tree many apparently individual trunks belong to the same organism with an extensive understory below ground which might be thousands of years old. All trees are involved in a substantial understory communicating with each other in ways that we can barely imagine let alone comprehend. Most of the ancient forests in Europe were cut down before science revealed the scale and complexity of life in them; yet, we still continue to fell forests as if there was an inexhaustible supply rather than one that could take as long to replicate as humans have been recording our history.