Transcriber: Daniel Harris-Pascal Reviewer: Denise RQ
When I was asked to speak here at Tedx Canberra
as a passionate ecologist and designer,
I could not resist presenting on food production
and particularly urban food production,
an area whose future is uncharted.
What is known about the future of food production,
is that the quantity of food that we produce
needs to markedly increase
in order to meet the projected food needs for a growing population.
Unfortunately, in the past,
increases of food production have come at the expense of ecosystems,
as resources are diverted away from the environment and into agriculture.
This is becoming an increasing issue
given the range of ecosystem services which an intact ecology provides,
including things like pollination, and the creation of soil.
If we are going to be able to produce the food we need in the future,
we need to do so in a way that supports and enhances ecosystems.
When I confronted this question a number of years ago,
about how we could produce more food,
I was passionately studying plant science and genetics.
However the solutions on offer were more of the same
and showed me a future where every forest was turned into a field
and every river used for irrigation.
Not feeling entirely comfortable with this vision of the future,
I began to investigate the food production practices used by other cultures,
to see if they could offer us any novel solutions.
I was lucky enough to be selected to participate in a program
at a botanic gardens in Hawaii.
I spent 3 months working with the gardens
and investigating the food production practices
used in ancient Hawaii.
When anthropologists first began studying food production in Hawaii,
they termed the Hawaiians as gardeners rather than farmers.
The Hawaiians were gardeners
because when they set out to discover the islands of Hawaii,
they took with them in their canoes 30 species of plants.
Upon arrival on the island,
they were able to cultivate these 30 species of plants
to grow almost everything that their civilization required.
The Hawaiians were gardeners
because rather than just arbitrarily putting up paddocks on the island,
they understood the island ecosystem,
and how the different parts of the landscape interconnected.
Food production in Hawaii was organized around the catchments.
This is a cartoon from the Botanic Gardens where I worked.
At the top of the catchment, the ecosystem was left intact
to provide ecosystem services
to the agriculture and food cultivation that occurred downstream.
These services included crucial things like making it rain and filtering water.
Further down the catchment,
the Hawaiians had an amazingly landscaped island,
and they would cultivate in these areas taro and tree crops
through an impressive system of aqueducts.
However, when they returned the water
that they used for irrigation, to the river,
it was full of silt and very high in nutrients,
and this could damage the reef
which the Hawaiians relied upon to produce fish.
The Hawaiians designed a solution around this,
and would create a series of fish ponds at the mouth of each river
and this turned those nutrients into another food yield.
I was amazed by the integrated food production systems
which I saw present in ancient Hawaii,
and couldn't wait to get home and see if they would work here.
But a seed of doubt crossed my mind;
It was all well and good if this would work in the tropics,
but I was planning to return to Canberra
which as we felt over the winter months is a far cry from a tropical island.
(Laughter)
Upon doing further research, I was pleased to find
that there were a range of cultures from a range of different climates
that utilized a form of food production
that resembles gardening more than farming.
One of the big myths of civilization is that people were hunter-gathers;
one day discovered agriculture, and we never looked back.
The reality is there is a third way,
which was practiced by people around the world
and more resembles gardening than farming.
This is known to be older than agriculture
and is today termed forest gardening.
There are forest garden cultures from around the world,
In Australia, Asia, Europe, Africa, and the Americas.
The best studied examples include the oak woodlands of California,
the Araucanian Forests of Chile,
dehesa systems in Mediterranean Europe
and parts of the Amazon rainforest.
What is amazing about these systems is that when Europeans encountered them,
they first just thought they were wilderness,
not realizing that they were actively cultivated by people.
All of these cultures would cultivate the whole landscape,
they were able to harvest from tree crops
and because the ecosystem and the food production were tied together
they were also able to raise livestock,
undertake hunting, and wild harvesting.
Over the last 30 years,
a range of people have been studying historical examples of forest gardening
and scrutinizing them through the modern lenses of ecology, botany, and forestry.
Lucky for us, the theory stacks up.
It is possible to produce food and maintain ecosystem services,
and it is possible to grow a range of plants together
so they cooperate rather than compete.
Forest gardening today is not about a romantic return to the past,
but rather a modernization of working examples from the past
to provide for our needs in the future.
I was swept up in forest gardening,
I devour every book and every website I could find on it.
I came to understand there are three key principles
that make a really great forest garden.
The first thing you need in a forest garden
is you need perennial plants,
plants which grow for more than one year.
Because perennial plants grow for more than one year,
they tend to develop extensive root systems,
which reach deep down into the soil,
and enable them to access water and cycle nutrients.
With these deep root systems,
perennial plants form associations
with soil microbes and things like earthworms, which we saw earlier.
They create and cultivate a vibrant living soil food web,
and this is able to support the perennial plants over time.
The second principle that we find in a forest garden
is it is a polyculture,
many different species of plants growing together.
Now if we went out and randomly selected some plants
and started growing them in the same space,
it's likely that we'd get competition as the plants would have similar needs.
A forest garden gets around this through the use of layers.
Because we select plants that have slightly different shapes and sizes,
we are able to grow them in the same space without them competing too much.
In a forest garden, we can cultivate a canopy layer of fruit trees,
shrubs below them, and even a layer of herbs below that.
These systems become incredibly efficient
because we are now gardening both horizontally and vertically,
above and below ground.
The third principle which we find in a forest garden
is that a forest garden becomes a model ecosystem.
An ecosystem is defined
as the interactions between living and non-living elements in a system,
and if we just took these plants and put them together in a garden,
all we would have is a collection.
To be a model ecosystem, these plants need connection.
To create connections in a forest garden, we need to use the workers of the forest.
The bees, the birds, the insects, and the microbes that create the interactions
that make a forest ecosystem abundant and resilient.
We can easily do this in a forest garden, and the ecosystem that we create,
can provide ecosystem services to all forms of production.
So, how do these principles work in practice?
This is my friend Cam's forest garden,
and my friend Cam really wanted to grow peaches,
so he planted a few peach trees.
In order to produce a good crop of peaches,
this tree needs access to nutrients,
assistance in pollination, and protection from pests.
Conventionally, nutrients would be provided to this tree
through the use of synthetic fertilizers,
but these are known to damage soil food web which this tree relies upon.
Pest control would be undertaken through the use of insecticides,
but these are known to kill off the pollinators
that the peach tree relies upon.
In a forest garden, we are trying to use our layers and these connections
to create associations between the plants and the forest garden.
This is kind of like companion planting but on a much bigger scale.
This peach tree is growing in association
with plants that bring nitrogen and nutrients into the soil,
plants which provide habitat for insect eating birds,
and a range of herbs
which provide flowers and food for pollinators throughout the year.
It's much easier for this peach tree to get
the nutrients for the needs that it has,
and it can produce many more peaches as a result.
These ideas go beyond our backyard
as an example of how forest gardening could apply to modern agriculture,
I often think of the example of almond production in California.
There is one valley in California
which produces 30% of the world's almond crop,
so as you can imagine, there's a lot of almond trees.
Once a year, when the almond trees are in flower,
bees and beehives need to be trucked and even flown in from around the world
in order to undertake pollination of the almond trees.
This is required
because there are none of these layers or ecosystem connections
which can support pollinators throughout the year.
Through the application of forest garden principles
and a little bit of thoughtful design,
a population of pollinators could be supported
in the valley through the year and we would produce many more almonds,
with less human effort, and less fossil fuels.
This example of almonds is not an isolated incident.
Most of the food crops around the world are limited by pollinator availability,
to the point where in some countries, pollination is now undertaken by hand.
Forest gardens can increase the amount of food that we produce.
Even if our main crops are not coming from the forest gardens themselves,
the ecosystem services that a forest garden creates
can benefit all of our agriculture and food production practices.
I was swept up, maybe even a little obsessed by forest gardening,
and I started to design and plant forest gardens
in backyards around Canberra, farms around the region and even a few schools.
And it was during this time that I realised
just how much potential forest gardens had
to help us produce the food we need in the future.
You see, another trend about our food production was pointed out to me.
in addition to producing more food,
we also need to change where we produce the food that we eat.
Around the world, there is an ongoing trend of urbanization
as people leave rural areas and start to move into the cities.
This is an issue because it is currently people who live in rural areas
that produce the majority of the food that our cities consume.
If we are going to produce the food that we need in the future,
we need to bring food production into our cities,
so that cities are providing for themselves.
In response to this need,
urban agriculture movements are forming around the world
trying to rethink and re-imagine how our cities relate to food.
I believe that Canberra has an incredible amount of potential
to be a world leader in urban food production.
Canberra has this potential given its history as a Garden City.
Garden Cities was one of the first ideas of design
which tried to integrate urban areas and food production.
As a Garden City, following the foundation of Canberra
over a three-year period, more than a million trees were planted,
and many of these trees included forest garden mainstays
such as chestnuts, walnuts, apples, and plums.
As a Garden City, Canberra was designed to incorporate
1/3 agriculture, 1/3 industry, and 1/3 housing.
As a result, Canberra has an abundance of green space in our urban areas,
a much higher proportion than many cities.
We tend to think that these green spaces are ecologically intact,
but many of ours in Canberra are ecological deserts.
There are no layers,
there are none of the interactions that make an ecosystem function.
These spaces have potential,
and this was demonstrated to me by my friend Paul.
Paul is an avid forest gardener who lives in the south of Canberra.
Being slightly obsessed by forest gardens he soon ran out of space in his backyard.
However, luckily for Paul, he looked over his fence once day,
and saw one of these neglected green spaces
that was just growing grass.
Paul couldn't help himself,
and he started to plant a range of fruit trees,
and today the space supports apples, peaches, pears, cherries, and plums.
Paul planted a range of support species,
native shrubs including acacias, wattles, grevilleas and hackeas.
Below these, Paul has cultivated a whole range of herbs
which provide flowers throughout the year
and a number of greens which passers-by can pick and eat.
People who walk along the bike path
are greeted with the sight of an abundant ecosystem,
the air is full of the sounds of birds and bees,
and the smell of flowers floats on the breeze.
If one person can do and achieve this with an hour a day,
imagine what we could do as a whole city.
Canberra has some great examples
of how we've revitalized our urban areas and rebuilt our urban ecosystems.
Many of you will be familiar with this scene in Canberra.
In the past, previously vibrant creeks and rivers were covered with concrete
in order to manage high flows of water coming off our urban environments.
Unfortunately, this has led to a lot of problems in Lake Burley Griffin,
as nutrients and pollutants are washed into the lake.
Luckily, some urban designers began to rethink and reimagine
what was possible in our urban catchments,
and today, in Sullivans Creek catchment,
a number of constructed urban wetlands are present.
These urban wetlands provide an ecological service to our city.
They slow-down and clean up the water that goes down our drains
before it gets to the lake.
Additionally, the urban wetlands have become hubs for urban wildlife,
and unsurprisingly, given this,
they have become a favourite spot
for the Canberra community to gather on sunny afternoons and weekends.
I believe that we can transform our parks in a similar way
and turn them into spaces which are producing food
and cultivating urban ecology.
It is time for Canberra to move beyond its initial vision as a Garden City
and see itself as a world leading Forest Garden City in the 21st century,
integrating urban ecology, food production, and urban lifestyle.
Forest gardens are part
of the food production solution for the future;
without them, maintaining our ecosystem services
while we increase the amount of food that we produce
will not be possible.
While it is likely that a diversity of solutions will be required
to the produce the food that we need in the future,
forest gardens are unique, as the only systems
that can provide and generate the ecosystem services
which all of our agriculture relies on.
If I've inspired you today, you can go home and start forest gardening.
You don't need to be an expert,
a forest garden can be started in a day and tended for a lifetime,
and there is a large community in Canberra who are willing to help you
and share plants to get you gardening.
If you've run out of space, or you don't have a backyard,
there are heaps of community groups starting to work with urban agriculture
to bring food production into our city.
Right now in Canberra, a community group is liaising with the local government
to gain access to a neglected green space near a local shopping center
with the aim to turn it into a community forest garden.
With the success of this project, I hope that many more will follow suit,
and we will see forest garden's appearing in our parks, public spaces, and schools.
I'd like to leave you with a forest gardening proverb
which embodies the long-term thinking inherent in forest gardening:
"You can grow vegetables for yourself, fruit trees for your children,
and nut trees for your grandchildren".
Perennial agriculture doesn't happen overnight,
a model ecosystem doesn't work out of the box,
it needs time to grow, and develop, and [form].
If we start cultivating them in Canberra today,
they will be online for us tomorrow,
and we will see Canberra lead the world in integrating urban ecology,
urban food production, and urban lifestyle
as a Forest Garden City for the 21st century.
Thank you.
(Applause)