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Monday, September 6, 2010

300 year old Food forest in Vietnam

300 year old Food forest in Vietnamese Suburb

Geoff lawton discovers a 300 Year old Garden tended by a Vietnamese family for 28 generations.
I love this Clip because i too search out old suburbs and where i always find the most interesting plants and emergent ecologies.

Old soils built up layer by layer from gardening and human activity, with Domestic plants and animals that have thrived over centuries of climatic variation. In Australia this situation is easy to find but like everywhere becoming a more and more scarce resource as cities intensify and modernize.

Old Public gardens are also very valuable for the Permaculture designer as they provide not only the tried and tested propagation material to start new gardens, but also the knowledge of what mature plants look like, their accumulated community of associated plants, wildlife and soil biota.

Finding an ancient Oak or mulberry, or in the tropics a 100 year old Mango tree allows you to study what each tree does to the soil in which it grows and the plant nutrients, deep profile soil carbon qualities, or surface O-Horizon "duff" or the allellotoxins that species may bioaccumulate. A native example i recall from Fremantle is the community that forms about rottnest Island Pines (Callitris preissii), whoe duff and possibly allelotoxins create a habitat that allows the growth of a Pellitory herb, which in turn is the sol food source of the Blue skipper Butterfly. We do not yet know what range of special habitats exotic species are creating that will foster unique niches for increased biodiversity, although we have evidence that Old Moneterey/Radiata Pine groves provide a rich habitat for rare native Ferns, Mosses and terrestrial orchids. These habitats then also support the species that depend on these plants. The importance of Mature pines to endangered Black cockatoos is well known, and Urban Mango trees are well utilised by endangered fruit bats and local bird species.

Old trees in mature urban settings allow study of how exotic plants integrate into the ecology and how they interact with native species and provide valuable habitat. What kinds of lichen,moss, algae, vascular epiphytes and fungi adapt to its bark? What invertebrate diversity lurks among the canopy, on the bark and in the rootzone? What structural diversity does it provides for nesting or feeding Birds, Mammals or reptiles, and what epiphytes like to settle. And to humans what are the properties for Ammenity planning? Shade? longevity?  root stability, spread  and invasiveness?. Without this evidence a designer cannot design systems that are truly sustainable.Without real examples to survey and quantify we remain in the dark working with a very rudimentary theory based approach to Urban ecosystem design.   
These old gardens are of immense value, not only because we are working with species that do not occur naturally together, being separated by geographic boundaries, but also because many of our most valuable cultivated species are becoming very rare or are already extinct in truly wild settings. Wild Apples in Afghanistan or Wild Vanilla in mexico are on the verge of disappearing before we know how their original ecosystems worked. 

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