Minor Landscape: Volcanic, High and Low Island, Coasts, Wetlands and Estuaries.
Volcanic:
Volcanic slopes have a repeated angle of repose which 64 degrees; this steepness needs careful application of design to retain stability. The traditional Ohana system achieved this with long wedge shaped village lands designed and maintained from forested top slopes down through multiple mixed systems to the beach, and out onto the coral reefs. Soils are usually rich and large ranges of crops are possible. There are two types of lava pahoehoe rock lava only good for 100% run off, and u’u which is like pumice, soft with many small holes, and this can be planted by digging mulch pits.
High Islands:
High islands are mostly granite or basalt rich in flora and fauna with humid to arid aspects. It is important therefore to study winds and rainfall carefully. Keyline system water design with ridge dams and terraces are all possible in these landscapes. Lagoon catchments and shorelines are valuable assets to designing sustainable systems. Special problems can be cyclones, tsunami, earthquake, mudflow, lava flow, cinder flow and volcanisms.
Low Islands:
These are usually quite arid and need very serious attention to windbreak design and planting, with all foreshores planted, as winds are bi-modal. On coral islands, all rainwater soaks into the freshwater lens through the platin layer and this lens water cannot be pumped and is depleted if polluted. Swales do not work and mulch pits and deep pit gardens close to the lens are the only possible system. These are the traditional systems of these islands. Dry compost toilets are the only none pollutant system, especially where over-population has caused problems with the traditional system of using the beach below high tide.
Coasts:
Coasts always need frontline windbreaks of salt-resistant, waxy or needle leaf, sand-blast species with thick and fibrous bark. The alkaline beach sand needs humus and soluble sulphates and oxides to offset the alkalinity, deficiencies in zinc, copper and iron (non-soluble in alkaline) are common. When establishing plants in sand, sawdust and paper lower P.H. and hold moisture. Planting in woven baskets and large cardboard boxes are good techniques.
Wetlands:
Marshes and wetlands support rich yields of edible plants, shellfish, fish, water fowl and honey producing species. The Chinampa system is recorded as the world’s most productive sustainable agriculture. A pattern of 50% land and 50% canals, it uses banks next to the water to maximize the productive edge in a system of water-land nutrient exchange in harmonic effect. Swampy and marshy land is ideal for this type of development. Ducks are the main livestock and they cycle nutrients, returning potash to the water and the land. Fish are marginal edge feeders and are well supplied. Crustaceans, shellfish and edible emergent plants are all possible. Floating water plants grow fast and filter suspended nutrient. Some harvest nitrogen and can be mulched on to the land, as water holding, seed free, fertilizing mulch. With trellised crop over the water space fences are incorporated, and harvest can be by a small boat with the water supporting the weight of the harvest while boating. Occasionally canals are drained and nitrogen rich mud scooped onto the banks.
Estuaries:
Estuaries are rich species areas with shellfish, fish, water fowl and many types of sea-grass useful for mulch, fodder and insulation. Fish traps, fish farms, shellfish farms, sea grass harvest and enhanced habitat and mulch traps can all be design as sustainable.
Designer’s Checklist: Check data on average rainfall, temperature, and wind speed and direction for the region (often found by contacting the Bureau of Meteorology). (See page 135 of Designer’s Manual).
References:
-Chang, Jen-hu, Climate and Agriculture, Aldine Publ. Co., Chicago, 1968.
-Halfpenny, James, Winter: An Ecological Handbook, Johnson Books, Boulder, Co., 1989.
-Klocek, Dennis, Weather and Cosmos, Rudolf Steiner College Publications, Fair Oaks, Ca., 1990.
-Mollison, Bill, Introduction to Permaculture, Tagari Publications, Tyalgum Australia, 1991.
-Mollison, Bill, Permaculture: A Designer’s Manual, Tagari Publications, Tyalgum Australia, 1988.
-Odum, Eugene, Fundamentals of Ecology, W.B. Saunders, Toronto, 1971.
-Schaefer and Day, Atmosphere: Peterson Field Guide, Houghton Mifflin Company, Boston, 1980.
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