Urban Agricultural Systems Inspired By Nature Can Mitigate Climate Change

As climate changes and extremes become more common (floods, drought, storms, etc.) growing food – especially in monoculture – will become more challenging. Monocultures rely heavily on external inputs.

Forests aren’t immune to climate change, but they’re less susceptible because of the connections they contain – forests are diverse, and the end of every process is the beginning of another. Forests cycle water, nutrients, and create microclimates conducive to life.

Cities are like forests. Cities are places for maximizing connections, and they’re filled with opportunity. Whereas a forest might cycle water, nutrients, and energy, cities cycle ideas, information, culture, and resources.

Ecologists describe the border between two ecosystems as an ecotone – a special place where the diversity of both systems some meet. If we could bring nature into the city, we could create a system with all the variety and potential of each separate systems – while creating unique opportunities for these systems to interact in beneficial ways that solve problems.

Here’s a secret – nature loves cities. Nature will colonize even the most inhospitable urban environments. And as it does, it will hold onto water, cycle nutrients, and create microclimates. We often fight the parts of nature best adapted at doing this.

The key to blending nature and cities is to link them in creative ways – in ways that turn problems into solutions. (Drink your problems away. Root-beer from invasive plants).

In cities, we tend to collect and move water away from our landscapes. Forests, in contract, capture excess water when it’s wet and put it to use when it’s dry. Forests cycle their resources – using water twice is the same as having twice as much water.

In the face of climate change, we can take inspiration from nature and integrate passive water harvesting and storage into cities – especially when combined with the potential to grow food. Small changes in topography can direct water to the soil where it can be accessed.

Here’s a water harvesting feature (swale) going into the Parkallen Community Garden. It’s built on contour and is designed to spread and soak water along the length of the garden.

Once planted, fruits and vegetables can access free water stored in the soil. This simple technique stores excess water during wet periods and makes it available when it’s dry – mitigating floods and drought.

Ecosystems don’t create waste – they cycle it. Though, we tend to bag ours and send it to the landfill. When we throw out our organics, we’re robbing our landscapes of essential nutrients. They’re called leaves for a reason.

Watering non-food producing monoculture designed to shed water then bagging and throwing away the result is insanity. This landscape could capture and process the water that lands on it. It should cycle and accumulate its nutrients. It could be producing food.

This patch of lawn has been converted into a raspberry garden. Beneath the ground, water harvesting features collect water from the roofs and spread it across the length of the yard. Covered with mulch the beds soak up excess water like living sponges and make it available to the plants. These simple techniques reduce flooding, reduce drought, cycle waste, and grow food.

This vegetable garden is growing on top of a series of water harvesting features that take water from the roof of the house. A bed of organic much is added on top and planted with vegetables and perennial food plants.

When I first started working in this yard it was unbearably hot – south facing and void of vegetation – the soil baked. After adding ten cubic yards of mulch, dozens of bags of leaves, and 24 straw bales the earth is coming back to life and the microclimate of the yard has transformed – it’s humid now and doesn’t get as hot or cold. This yard now captures all the water that lands on it and converts it to food.

Urban environments are exceptional places for creating and taking advantage of microclimates – especially for food production. These fruit trees are planted against a south facing fence to increase the length of the growing season. Water harvesting features below the ground bring water from the roof to the base of the trees.

Vast microclimates create large potential. The south-west facing retaining wall by the Quinelle bridge would have made an amazing fruit orchard – absorbing the sun’s energy throughout the day and radiating it back at night.

Just outside of Edmonton’s growing conditions (zone 4a) – the ‘resilient’ peach (zone 5).

Just outside of Edmonton’s growing conditions (zone 4a) – the American persimmon (zone 5).

Just outside of Edmonton’s growing conditions (zone 4a) – the largest fruit native to North America – the Pawpaw (zone 5).

We can choose to come together and create innovative food-producing systems that benefit the city and the natural world. Since 2014, I have been partnering with the City’s Roots for Trees program to plant thousands of native edibles in the river valley.

A forest is a community, and a community is a forest. It’s a dense web of connections, ideas, and potential. Working together is probably the single biggest strategy that we can adopt from nature to grow food and mitigate climate change.

There’s no shortage of places to do this – backyards, front yards, boulevards, vacant lots. The City of Edmonton recently released a list of public utility lots available for gardening.

One of my favorite things to do is reimagine the cityscape as food-producing ecological systems. I used to call this “postapocalyptic Edmonton”, but I’d rather see them in a preapocalyptic reality.

I will admit that some of my drawings are a bit tongue in cheek – but we have so much unused space, and we should be putting it to productive use.

This is a favorite of mine. West Edmonton Mall Community Garden.

How much food could we produce in the city? Probably not all of it – but let’s not underestimate the food producing capacity of many small players. What we need are people who are willing to try and the regulatory and political conditions conducive to doing so.

What I can tell you is that in addition to capturing water, reducing waste, and temperating the local climate these systems will be uniquely Edmontinain – like these, naturalized Goji berries left behind by Chinese market garden community.

Or these – Capilano apricots guerrilla planted in a city scrub bed sometime in the 60s. This is a uniquely Edmonton variety – it exists nowhere else int he world.

So let’s take inspiration from nature and create a city that cycles nutrients, tempers climate, and captures water and our imaginations.

Let’s create a forest city.