Throughout their life, trees, like all plants, are engaged in complex and intense biochemical activity.

- Through photosynthesis at leaf level thanks to the sun: substances contained in brut sap which is conveyed from the roots to the trunk's liber and on to the leaf via the petiole, are transformed by the tree into elaborated sap.
- Through respiration: the tree absorbs the oxygen it needs to grow through its epidermal tissue.
Flowers, fruits, wood and roots are produced by combining elaborated sap with oxygen. This oxidation produces carbon dioxide, which is expelled. We can therefore talk about veritable respiration.

- Through evaporation and transpiration leaves can combat the effects of heat. Transpiration leads to an immediate need for water at root level, by aspiration. It is this uninterrupted cycle that gets sap moving.