Zone 6? I have seen zones 1-5 discussed, with occasional reference to zone 0 (the actual house where 'we' sleep).
Zone 5 has always been referred to the 'natural' area where
no change takes place...nature's space...raw.
The Fibonacci spiral is based on the 'Golden Ratio', see
Wikipedia.
It would probably work out, if you had a spiral shaped piece of property.
However, in Britain, and all of her ex-colonies, an acre of
land (what a man and his beast could plough in a day) was typically 660 feet by 66 feet (
enough land to
feed a man and his family, with a minimum of U-turns for the ploughman/beast). Typically, a 5 acre plot is 660x330: 5 one acre plots,
side by side
If you bought a plot of land, that was roughly proportionately to the golden ratio, and had never been developed by man,
perhaps it could be zoned accordingly, but I see no advantage to that. Land is not a 2 dimensional quantity, despite what the realtor and tax man tell you. It is 4 dimensional: length, breadth, depth, and fertility. If it is raw land, a zone 5 must be preserved, to observe and study what is the nature of the land. This will instruct you how
best to develop the other zones.
If the land has already been altered to the point that there is no longer a zone 5 on site, you will need to observe neighboring zone 5's to best interpret what the nature of the land is, (and try as best as possible to restore that missing zone).
And, thanks for that link to Mollison. I had not seen that presentation yet. The best I have ever seen/heard him refer to the 3rd ethic.
Should be enough to shut down the 'moochers' that think we 'owe' them something.