I just read your comments in another thread and I want to make a suggestion a chapter in the new edition of your book: The plusses and minuses of adding materials to one's garden. I would think that pine shavings would be different from fir shavings which would be different from cedar shavings which would be different from alder shavings. The barks probably even vary a lot from the wood. The chapter could cover the big plus of the organic matter, offset by allelopathic stuff (acidic, tanins, etc.) and the C:N issues.
Well, maybe not a chapter - but it could be a great appendix.
Often times, people in these forums ask me about adding compost. And I reply that home made compost is about a hundred times better, IMO, than the best store bought compost. First, nearly all commercial compost in the pacific northwest has some level of clopyralid in it. It might even be safe to say "all" - but I'm not entirely certain about that. Next, nearly all commercial composts contain conifer wood chips: the acidity and the C:N problem can be mitigated; but the tanins and similar alelopathic things are significant - for some conifers more than others.
On the other hand, I've always thought that shredded alder is going to be alelopathic free. You might have some clopyralid, depending on whether any was sprayed around it in the last ten years. And there is some C:N issue, but that's to be expected with any shredded wood.
My positions on these things come from a mish-mash of bits and bobs accumulated over the years and it seems like something where your knowledge would already be about 40 times richer than mine. Add to that that you already have a book, plus you have the combination of scientific mind and ability to explain stuff like that to pleebs like me.
It just seems like one of those things where you're the perfect guy for the task. And I think such a collection of information would have a large impact on understanding toxins (both natural and artificial). And that section of your book alone, might move more copies! Yeah!