The terms are abridged from A-Z of tree terms: A companion to British arboriculture Second edition.
You can compare the full definition of ‘tree’ here with the online definition here.
Third Edition
The third edition of ‘A-Z of tree terms: A companion to British arboriculture‘ is now available for purchase, with large discounts for colleges, students and trainees.
‘A must-have reference guide for British arboricuturists’ ARBORICULTURAL ASSOCIATION