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)
