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- I saw the mention of aiming for 70% of converted cropland
as forage farming in the course notes and elsewhere.
I wonder, is that a golden rule of some kind?
Are we trying to achieve this in every design?
Can you elaborate on what we're trying to do here?
Why 70%, and when this number applies?
Well, for human settlement to be truly sustainable,
we kind of need about 70 to 80%
in some kind of forest cover,
and that forest cover can have very, very diverse
productive uses over time but not necessarily
harvested all at once, continuously harvested.
And that sort of knowledge comes with heritage,
you're passed on from generation to generation
because of the longevity of forest.
It's a very long living system
and it is continuously perpetual,
if we actually manage it the right way.
So you're never out of forest,
you're always managing a forest
and harvesting from a forest at a continuous rate.
So it's never stopping.
Now to gain stability,
if you look at the sustainable systems of earth,
there are massive areas in range land management
where very few people have very large areas of land
and herds of animals,
but it's kind of a baronial permanence,
and it doesn't help many people.
It's just one or two people over a very large area.
And then if you look at the ancient systems of China,
Japan and Korea,
century or two ago, you had a grain culture of servitude.
It was organic, but it was a massive amount of slavery,
almost labor, where there was huge amounts of organic matter
continuously toiled and turned around,
all the sewage systems, all the animal waste systems,
all the surplus product,
all of the surplus organic matter,
was continuously toiled back into a grain culture,
mostly rice, right, which was sustainable,
but made the people slaves
and you end up in a bloody revolution like that.
So if you look at the broad systems
that have been sustainable over time,
the only one that is truly sustainable
is the forest systems,
where people lived in forest settlements,
where 70 to 80% of the land was some sort of forest.
Now, if you look at the intricate farming systems,
and there aren't many,
that are truly sustainable out there,
you can look at the Ahupua'a systems of the Hawaiians.
That was a sustainable system managed by people,
but it was managed around water catchment exactly,
and a lot of it was steep, volcanic slope,
which are very steep
'cause the angle of repose of volcanic ash.
Now, when you analyze how much forest was in there,
it was a considerable amount of forest, at least 70%.
And the steeper top slopes were always sacred forest,
and then your long-term forestry was below that,
even with fuel woods like the kukui nut,
the candlenut was their fuel.
And then their food forest, mixed forestry underneath that,
and then it went into very specifically managed
wet paddy type taro fields
before it got to the village,
before got to the Tsunami belt.
So there was a protection from tsunami on the foreshore.
So there were often catchments to foreshore
in the Hawaiian islands.
And then you get the chinampa systems of Mexico
and parts of Asia, which are canals and water.
Canals and land based, so a 50% land, 50% water
with trellises over the canals and good forestry systems
as well as crops on the land base.
There was enormous amount of vegetative cover.
The whole thing was vegetated and a lot of forests
and a lot of aquatic system at the same time
that it was the most productive system ever documented,
most productive sustainable system ever documented,
the chinampa system.
And we can put the Ahupua's type system as for steep slopes.
We can use that type of thinking,
we can use the chinampa system for,
and in part of our design.
We can do chinampa-esque type systems.
Then we look at the date palm over story of the Middle East
and North Africa.
They were dry land systems, arid landscape,
but had an overstory of palm trees,
with up to 13 different fruit trees underneath
and very small clearings.
Only 1/4 to 1/2 an acre,
2004, 1000 to 2000 square meters, very small clearance
with a real dry land productive forest at random,
way more than 70% forest and mostly productive forest.
And there would have been steeper sections
that weren't so productive.
Then you've got the Sweden burn systems that are tropics.
Now you're in the tropics, two acre clearing for production,
but it was abandoned for 10 to 15 years when it regrew.
And these were literally in the wild forests,
in the tropical forest.
They're out there as examples, all of these.
So you've got way more than 70% there.
Now the fruit trees were grown on the walk from the village
out to the gardens, and there were multiple gardens
out along the walks from the village
and you didn't return to a main crop garden
for one to two years.
It's called the Sweden burn system.
And then you have, (phone ringing)
the cork and polk forest of Portugal and Europe.
Fantastic systems of temperate climate for us.
So that's where it all comes from.
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