From the much celebrated Claus Mattheck and Helge Breloer, (Lonsdale and Strouts), comes an arboriculture book about the signs of distress trees show us through their reaction growth.
The signs (body language)that trees give us have been documented numerous times by C. Mattheck but in this book it goes into detail on why trees grow the way they grow. It also has goes into the physical science of how the shape, size and hollows can compromise the stability of the tree as a structure.
t/R ratio, h/D ratio and others are in here.
At present the (much accepted) theory of these ratios is being pulled into question by another arboriculturalist Franz Gruber. Nevertheless this books information is crucial for the Arboricultural Associations Technicians Certificate, and the Professional Diploma.
Criticism of the book that lowers from a 5 to a 4 star is that the book on certain topics is hard to navigate around. You will find you require more of his books to use when reading and trying to understand cetain physics of the book. Also some of the information on decay detection equipment is a little dated.
That said it is interesting book covering the angles most commonly left by other authors, and not many people know more than the guys who put this book together. Feeds you the knowledge that is required to be inside the paperwork industry of arboriculture.