ABSTRACT
This chapter reviews how trees function, what makes them grow and what restricts that growth. It provides an insight into the biological, chemical and physical functions of trees to assist in the recognition of healthy growth, suitable growing conditions and plant problems. In harnessing light energy from the sun and transporting it downwards, the tree canopy provides a source of fuel for the rest of the tree. Plants are exquisitely adapted to harnessing radiant energy from the sun in their leaves, converting it to chemical energy and using this to manufacture organic carbon compounds from inorganic raw materials. This conversion produces a source of stored energy, in the form of carbohydrates. The production of carbohydrates within the leaves creates a local increase in pressure, forcing the sap along a network of specialised plant tissue known as phloem to where it is consumed by respiration to provide energy for other biochemical processes of maintenance and growth.
