SciTech

Author speaks about edible forest gardens

Consumers in large cities often hear of Florida-grown oranges or Idaho potatoes. But in a time when the world’s climate is sometimes unstable, city shoppers might find themselves purchasing products grown a lot closer to home.

In the first of four lectures called “Urban Farming — Reconnecting Our Farms, Food, and Community,” David Jacke, author of Edible Forest Gardens, spoke in Rangos last Thursday about the advantages of urban food forests in a world where climate change and global warming may transform our lives.

Jacke referred to these problems as “humanity’s quadruple threat,” which consists of a rising global population of about 77 million people per year, global climate change, destruction of the earth’s habitat, and high oil production.

Jacke said that global warming has caused the Arctic ice shelf to melt, putting polar bears in danger. In particular, large pieces of ice are shrinking and drifting apart, forcing polar bears to swim up to 60 miles in the sea to find food.

In an online publication by Canada’s Office of Urban Agriculture, President of the Urban Agriculture Network Jac Smit discussed some of urban farming’s benefits. In particular, urban farming reduces the use of chemical fertilizers because urban farmers use urban waste as fertilizer. It also reduces the amount of pollution produced from shipping food products across the world.

Jacke said that the goal of urban food forests is to produce high, diverse yields of different plant species, to have a self-maintaining and ecologically healthy food forest, and to improve economic stability. In addition, these forests are low maintenance and yield eight months’ worth of fresh fruits, vegetables and herbs.

Urban farming also enriches the soil through nitrogen fixation. Nitrogen fixation is the process by which nitrogen gas, which can’t be used directly by plants, is converted into useful nitrogen compounds like ammonia and nitrate, which are plant nutrients.

Jacke talked about the produce of edible forest gardens. These gardens mimic a natural forest in which fruits, nuts, vegetables, herbs, mushrooms, and other plants form symbiotic relationships. On his website, Jacke stated that gardens produce “high yields of food, fuel fiber, fodder, fertilizer, ‘farmaceuticals,’ and fun.”

Urban agriculture is an especially important resource for developing countries such as those in Africa and Latin America. According to the Resource Centers on Urban Agriculture and Food Security (RUAF), researchers expect that 85 percent of the poor in Latin America will be located in urban communities by the year 2020. In many instances, urban forests provide nutritional produce to individuals who cannot afford to purchase their own food.

Urban forests also benefit the community as a whole. In particular, households can grow their own produce and barter for income. Other enterprises brought about by urban farming include the packaging, marketing, and delivery of foods, thereby providing jobs to urban residents.

Jacke said that forest designs depend on four key aspects: community architecture, social structure, structure of the underground economy, and succession.

Community architecture is the design of a forest garden. In particular, forest gardens typically consist of diverse vegetation layers and various kinds of plants. Such variety leads to a diversity of bird and insect species, thereby offsetting the insect pest population.

The social structure consists of plants and animals that produce food and form symbiotic relationships. In particular, each organism in the social structure contributes to the garden’s biological processes. Jacke stated that to fully utilize the sun’s energy, for instance, developers must grow plants with different light tolerances — plants that thrive in shady conditions as opposed to plants that need a lot of sunlight.

The underground economy consists of the woody and herbaceous plant roots. Understanding the pattern of root growth is critical to establishing a thriving garden. If fruit trees can get a fraction of their roots deeper than the normal two or three feet of soil, they live longer, produce more fruit, and are more resistant to disease.

According to Jacke, edible forest gardens also serve a more humanistic purpose.

“Forest gardening helps us take our rightful place as part of nature doing nature’s work, rather than as separate entities intervening in and dominating the natural world.”