edge zones

Lee Flier lflier at mindspring.com
Tue Aug 12 00:39:50 EDT 1997


Lawrence wrote:

>Would anyone care to expound on the design and usage of
>edge zones  and patterning in the context of permaculture
>systems?

OK, I'll bite.

Yes, the patterning in design and the use of edge zones is very important
in maximizing use of resources on any site.  It's a really underrated and
fascinating area of study.

"Edge zones" occur naturally at the transition point between any two media.
 This could be between air and water, water and soil, forest and field,
valley and slope, etc.  The interesting thing is that the edges of anything
are always very dynamic and productive compared to the interiors.  For
example most farmers know that the yields at the edges of grain or
cornfields are almost double what they are in the interiors!  Also if you
look at a pond, there is more potential diversity of species at the edges
of ponds than in the middle.

So, in designing sites we want to maximize the amount of "edge".  In the
case of the grain fields for example, you can plant trees, (together with
herbs, fruit bearing shrubs, vining plants, tubers and anything else that
will do well under trees), and then run 6 foot wide swaths of grain in
clearings between the  trees.  This gives you a "perpetual edge" and you
will get nearly the same yield you would have had if you'd planted all
grain, PLUS the yield from the trees and other plants.

Likewise with a pond, if you make "fingers" all around instead of a simple
round or oval shape, you will get much more edge which will yield a lot
more in the same area.

Nature itself has a tendency to arrange things into certain patterns that
appear random to us if we aren't conscious of them, but which are often
optimized to create edge (as with the "finger" shape which is also in an
oak leaf, the "branching" shapes of rivers, lungs, and tree branches, etc.)
 The shape of a mushroom is also prevalant; trees, bones, the flowforms of
running water, and many other things take on this shape.  The patterns, the
reasons why the patterns occur, and the connections between them are
endless but the basic ones are fairly simple, and a lot of aboriginal
"abstract art" is really a map of these natural patterns, a way to pass
knowledge of them down to the children.  Most westerners see this artwork
and see it as purely aesthetic, not having a clue that they're looking at
the equivalent of a school textbook - only a lot easier to memorize!

The idea in learning these natural patterns is that by imitating them in
human designs (rather than patterning everything after the needs of
machinery, such as in straight lines and squares), we will get more out of
the system with less work and less use of resources because these are the
patterns things "want" to fall into without our help.  We in fact are
wasting resources every time we try to design a system that runs counter to
these patterns.

Well that's the basic idea... I'm sure others will have something to say too!

= Lee =


==================================
Lee A. Flier
lflier at mindspring.com
Atlanta and Ellijay, Georgia, U.S.A.



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