In it there is proof that trees communicate with each other through the roots, different species can talk to each other, they share nutrients and sugars between each other and talk with fungi. Eg. they can warn each other about insect attacks and react with bitter leaves.
My favourite trivia from the book is that there are three currently accepted answer for how trees circulate water: capillary action, transpiration and osmosis.
Capillary action is the same force which holds rain drops together - that should push the water up in the trunk fibers.
Transpiration is basically works like trees evaporates (exhale) water through its leaves and that creates suction.
Osmosis is that if sugar in one cell is higher than the neighboring cell, the water will flow towards the more sugary one until both have the same amount of water.
Now, capillary action cannot work for more than 1 meter height, and water flow is highest in the trees at spring before the leaves open up so that rules out transpiration. Osmosis can only happen in the roots and leaves because trunk contains long tubes for water and not cells.
Which leaves us... Yeah. We don't know :D
A tree's year is as our day. Can you imagine what a 200 day full lifespan might be like?
I've cleared forest, and watched the white oaks that were suddenly in the open pop out and double in size in 15 years. 60+ year old trees. They seem appreciative, as far as i can tell. They all started leaking sap to feed bees immediately; the forest dwelling siblings nearby do much less of that. Perhaps this is bragging on their advantageous position.
I think the actual thinking happens at a larger level. Areas of forest linked by fungi underground have moods, that we can feel a little.
That’s exaggerating. The life expectancy of a human is in the order of 30,000 days.
Reading https://en.m.wikipedia.org/wiki/List_of_oldest_trees, and ignoring clonal trees (https://en.wikipedia.org/wiki/Vegetative_reproduction), 6,000 years seems to be the upper limit.
So with AI/LLMs, they're arguably not at all... they have little awareness of self, don't develop experiences or memories, but people feel like they may be conscious because they communicate well.
However something like a city or an advanced enough vehicle is fairly self-aware. Cities deteriorate with crime, but also develop the mechanisms to fight crime as well. Same with garbage, GDP. There is some parallel to the systems that goes on in your body, how blood transports resources, parts regenerate from those resources, and so on. Anthills have about the collective intelligence of a dog, but an ant is pretty dumb.
On the other hand, some animals aren't very good with it. Arguably a newborn baby, or an old person nearing death isn't very conscious. You could argue these humans still have souls, which could mean that the concept of a soul is not strongly related to being conscious.
I don't know enough about trees, but I'd ask: do they have pain receptors? Are they capable of focus? Predators have eyes in the front of their heads to focus their attention on a target, which also allows for more advanced thought and rationality. Can they interact with the environment to protect themselves? Someone here mentioned that trees communicate, but that could also mean that a tree may not be conscious but a forest might be.