The great oval of the design represents the egg of life – quantity of life which cannot be created or destroyed, but from within which all things that live are expressed.
Within the egg is coiled the Rainbow Serpent – the Earth-shaper of Australian and American aboriginal people.
Within the body of the Rainbow Serpent is the tree of life, which expresses the general pattern of life forms.
Its roots are in Earth, and its crown are in Rain, Sunlight and Wind.
Elemental forces and flows shown external to the oval represent the Physical Environment, the Sun, and the matter of the Universe; the materials from which life on Earth is formed.
The whole cycle and form is dedicated to the complexity of life on Earth.
(Source: Permaculture: A Designer’s Manual by Bill Mollison)