15. The Metabolism of the Tree
All the processes that take place in water are reflected once again in
the individual forms of vegetation. Viktor SchaubergerSap movement
Viktor Schauberger has transformed our understanding of the
metabolism of the tree. He showed how the movement of the sap
under the conditions of both natural growth and of unnatural light-
induced growth is determined by the temperature gradient within
the tree itself, and by the external light, heat and cold.
The solution, transport and deposition of nutrients, as we saw in
Chapter 14, are functions of the temperature gradient. Salts and
minerals are precipitated with cooling, when light and air are
excluded; however, they are precipitated with heating when exposed
to light and air. Under a positive temperature gradient, as the sap
cools towards +4°C (39°F) or is maintained at this temperature, the
highest quality nutrients are precipitated last. Under a strong nega-
tive temperature gradient and with light and heat, the opposite hap-
pens; only the lowest quality nutrients are expelled, the highest
quality not being transported at all.
We saw that the growth of shade-demanding trees takes place
largely in the crown where the air temperature is usually higher
than at ground level. The tree's overall shape is cylindrical, with few
lower branches, because there is no need to protect the trunk
against light. Lacking horizontal lighting, the trunk does not suffer
large temperature fluctuations, so it produces closely set annual
rings. The temperature in the trunk reduces from the outside
inwards, resulting in an even deposition of growth material, which
means high quality and dense timber. These shade-demanders have
a slender girth because of their strong vertical sap movement, high
health and associated levitational energies, that in a mature tree
enables it to withstand gales.
When a shade-demander is planted out in the open it has to cope
with unnatural levels of light and heat, protecting itself as quickly
as possible by sending out branches right down to the ground, at the
- THE METABOLISM OF THE TREE