In addition to helping fruit growers, fruit tree enthusiasts, students and fellow scientists better understand how fruit trees work so they can manage and study them more effectively, I hope that, by reading this book, the reader gains a greater appreciation of the physiological, structural, ecological and evolutionary capacity of trees to cope with, and adapt to, short- and long-term changes in their environment. This book is the culmination of 40 years of research on trees, analysis of other scientists’ research, and teaching university students and fruit growers about fruit tree physiology and tree fruit production.