To: permaculture@listserv.oit.unc.edu Subject: Re: edge zones From: Lee Flier Date: Mon, 11 Aug 1997 23:39:50 -0500 In-Reply-To: Reply-To: permaculture@listserv.oit.unc.edu Sender: owner-permaculture@listserv.oit.unc.edu 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@mindspring.com Atlanta and Ellijay, Georgia, U.S.A. References: edge zones From: "Lawrence F. London, Jr."