Permaculture Designers Manual
CHAPTER 4 – PATTERN UNDERSTANDING
IN PERMACULTURE
Section 4.6 –
The Harmonics and Geometries of Boundaries in Permaculture
The amplitude, configuration, and periodicity of an edge, surface, or boundary may be varied by design. Edges and surfaces may be sinuous, lobular, serrate, notched, or deliberately smoothed for more efficient flow. While we may deliberately induce turbulence in salmon streams by using weirs, we are painstaking in using smooth and even conduits for energy generation in wind or hydraulic systems.
We can deepen areas of shallow streams to make pools, or to prevent stream bank erosion, or to reflect solar energy to buildings; all these are manipulated to achieve specific effects on their boundaries or surfaces. Notched or lobular edges, such as we achieve in a plan by following hill contours, afford sheltered, wetter, drier, hotter or more exposed micro-habitats for a variety of species. Serrate or zigzag fences; not only stand on their own but resist wind-throw much better than straight barriers.

Lobular embankments, like the keyhole beds of Figure 4 .7, are obviously sheltered, spacious habitats for gardens and settlements. As for surface and flow phenomena, we can partition water surfaces to reduce wind effect, or design to deliberately create turbulence and wind overturn. Islands, quoins, and rafts of many shapes have as many uses and deflect flow to increase condensation or to encourage sand and snow deposition or removal. Surfaces can be pitted, ridged, spiraled, mounded, tessellated, tasseled with plants or brush, paved, and sprayed to stabilize mulch, mulched, or smoothed for water runoff. Insert Here When a boundary separates two things which differ, there is an opportunity for trade, transactions or translation across the border (Figure 4.8).
When the boundary itself is difficult to pass, where it represents a trap or net, or where the substances and objects attempting to pass have no ability to do so, accumulations may occur at the boundary. Examples of this lie all about us, as stranded shells on the beach, people lined up at visa offices, ad cars at stop lights or curbsides. People are, at heart, strandlopers and beach-combers; even our dwellings pile up at the junction of sea and land, on estuaries (80% or us live at water edges), and at the edge of forest, river, marsh, or plain.

Invariant ecologies may attract the simple-minded planner, but they will not attract people as inhabitants or explorers. In design, we can arrange our edges to net , stop, or sieve-through animals, plants, money, and influence. However, we face the danger of accumulating so much trash that we smother ourselves in it. Translators keep the flow on the move, thereby changing the world and relieving it of its stresses. The sensible translator passes on resources and information to build a new life system.
There are innumerable resources inflow. Our work as designers is to make this flow function in our local system before allowing it to go to other systems. Each function carried out by information flow builds a local resource and a yield.
If you now carefully observe every natural accumulation of particles, you will find they lie on edges, or surfaces, or scattered nearby, like brush piled up against a fence (Figure4.9). We can use these processes to gather a great variety of yields.