This was a great book. It probably helps if you're into trees, but even without that proclivity, there is a lot to recommend it. The characters are well developed; not just one central one, but a whole raft and not just at one moment, but with a development over time and through the book. The plot has great twists and turns, but what is even better is that you are often so caught up in the particular moment that you're not bothered about the plot as a whole.

There is only one negative point I have, and I am not sure if it is really fair. This is of course a work of fiction, but not only does the book contains a vast quantity of facts about trees, but it is also rooted (as it were) in historical events. I don't know so much about 'eco-terrorism' in the USA in the 80s, but as a botanist I do know something about the development of understanding of how plants (not just trees, incidentally) communicate with each other. Firstly, that whole branch of science is presented as being encapsulated by one lone fictional individual. I understand that that makes for a better story, but it does feel a little unfair on all the hard working scientists who actually did (and are still doing) the work. And I wonder if non-specialists might mistakenly think that because the character is fictional, so perhaps the communication as well? Something of an acknowledgement might have been in order. Secondly, that development is presented as being something rejected by established science. That might have been so for forestry, I don't know, but certainly for plant ecologists, it fitted so well with what was already known that I don't think that was a a problem. I remember when I was a botany student in the 80s hearing about research showing that the large number of small beech saplings in a mature forest stay small for years, not because the light was too dim to allow them to grow, but because the growth was switched off by the green light filtering through the leaves of the adult trees. When a tree falls, the switch is thrown and the ready-and-waiting saplings grow up. What is relevant is that they do this using mycorrhizal connections to the adults. The adults actively pump nutrients into the growing saplings at that moment, to maximize their growth. They are indeed a system, not just individuals. From that, it is a small step to also seeing airborne chemical communication as plausible. 

That all having been said, this remains a superb book. I will certainly return to it and read it again, which (for me) is very unusual.