Permsteading.com

"Edible Forest Gardens" by Dave Jacke with Eric Toensmeier.

http://www.edibleforestgardens.com/

This is a two volume set of books that I have been engrossed in for a week or so now. A wealth of real world information, visits and balanced reviews of existing forest gardens, including Robert Hart's and Martin Crawford's. My favorite section so far is the Pattern Language of Forest Gardens section which references Christopher Alexander's landmark book. Totally serendipitous that my neighbor dropped that book off a day before these arrived. Anyway, these two books aren't cheap, but I have gotten my money's worth out of them already in the short time I've had them. Excellent indexes list useful plants, which I've found incredibly informative. Overall, I would strongly recommend these to anyone interested in the subject.

Yes Lemicha, Volume One has a chapter titled "Structures of an Underground Economy" which goes into great detail of root structure and much more. I also found Robert Kourik's "Designing and Maintaining Your Edible Landscape Naturally" a great resource in this regard. He does a wonderful job of discussing the various root systems and how to design using that knowledge.