What is Urban Ecology and Why is it Important?

An article by Ryan Taylor of Colorado State University and representing the Sustainable Secure Food Blog

In the summer of 2007, humanity reached a milestone. For the first time in human history, more people were living in cities than in rural areas. Those people need food, clean water and air, and other necessities of modern living.

At the turn of the 20th century, with more people living in cities, residents lived further from food production sources. This put a burden on the agricultural land for food production, and meant an increase in transportation costs. Additionally, handling fresh food became a new industry within our urban culture.

City street in New York crowded with people.
In 2007, humanity reached a turning point. More people live in cities than in rural areas. Photo: Morguefile

Urban ecology provides answers to these and many other questions so that our cities can thrive—without harming the people, plants, and animals living there. This new area of science can also benefit those areas. It can help cities learn to re-use natural resources through recycling of nutrients that are hyper-consolidated in the urban environment.

One of the interesting questions urban ecology wrestles with is urban food production and the impact it has on cities and human health. A well-known ecological principle that pertains to diversity is that the more species diversity you have in a system, the healthier that system is. It’s also more resilient. For example, the Irish Potato Blight occurred mostly because farmers were only growing one type of potato. This made those potatoes—and the entire crop—more susceptible to any insect or microbial attacks. (For more on that, read this blog.) As a result millions of people were displaced from their homes and their heritage.

Invasive species also create similar problems to those the potato farmers encountered. The emerald ash borer which is native to Asia is one such story. The small green beetle has come to North America. This beetle has few natural predators on its new continent. Thus it has started to destroy our native ash trees (Fraxinus spp.). Currently 15% of Colorado’s urban forests are ash, and there are 1.45 million ash trees alone just within the city of Denver. That meant that when the emerald ash borer migrated to the area, there was no natural defense against this invasive insect. Without treatment, the trees were killed. It’s definitely a tragedy—but one that we can definitely learn from. Whether it’s through diversification within cropping systems or the exclusion and management of invasive species, urban ecology provides us with the tools to do better in the future.

Apple on a tree.
As urban trees die and need replacement, they can be replaced with fruit-bearing trees, such as this apple. Photo: Morguefile

As these ash trees die or get removed, they can be replaced with food-producing varieties of different fruit trees: cherry and apple, pear and mulberry. Not only are these food-producing trees beautiful when they bloom, but they provide pollen to the bees and other pollinators. The Beacon Food Forest of Seattle, Washington produced 4,250 pounds of food in 2017! That’s on just a portion of the proposed seven acres of land the forest will eventually encompass.

Rooftop garden.
This urban farm is on the rooftops of student-oriented apartment buildings in Berkeley, CA. The rooftops are connected by exterior walkways. Up to 16 tons of produce is harvested each year. Photo:

Food forests aren’t the only way to integrate food production into the urban ecosystem. Small garden plots on empty lots and public land can be turned into community gardens. “Green” roofs can also serve as gardens and commercial greenhouses make up a thriving urban food production system that few of us hear about. Even your home garden can contribute to food production!

Urban food production might not feed the entire world, but it reduces the total miles driven bringing food to the city. This means less air pollution! It also helps to reduce food insecurity, and makes better use of the water we have transported and cleaned. Urban food provides verdant landscapes which soothe the mind surrounded by a jungle of concrete and steel. Food production impacts the city on many levels. Urban ecology influences how these resource decisions are made and how those decisions impact not only us, but also the plants and animals that inhabit those vibrant communities.

This article was sponsored and written by members of the American Society of Agronomy and Crop Science Society of America. Their members are researchers and trained, certified professionals in the areas of growing our world’s food supply, while protecting our environment. They work at universities, government research facilities, and private businesses across the United States and the world.

Garden writer and blogger, author of 65 gardening books, lecturer and communicator, the Laidback Gardener, Larry Hodgson, passed away in October 2022. Known for his great generosity, his thoroughness and his sense of humor, he reached several generations of amateur and professional gardeners over his 40-year career. Thanks to his son, Mathieu Hodgson, and a team of contributors, will continue its mission of demystifying gardening and making it more accessible to all.

9 comments on “What is Urban Ecology and Why is it Important?

  1. “…become a realization” – for ALL, to be involved with design and implementation.

  2. What several programs that promote sustainable development teach us, through reality of what transpires, is that economics drive the boat. Riding “shotgun”, is the reality that it takes a collective effort and buy-in to create and maintain continuity of vision. This is made difficult by the host of circumstances and states that people are in who live in these communities. In other words, a “one-stop-shop” approach is not possible. A great place to start in search of finding harmony, among all who live in a community, is the homeless population. Just as our larger ecological goals are NOT possible without contiguous habitat that can cut through developed areas, so too is our hope of having the goals outlined in this article become a realization. Otherwise, it just serves those “with”. Its much easier to say, “I am for ‘x’ when you have resources already”. This applies to jobs, housing, immigration, etc. Its why third world areas typically have less “environmental programs” or jobs relating to said field, because they have much more pressing needs – such as “how will we survive today?”.

  3. Yes, . . . but not practical. Those who live in cities, with minimal horticultural experience, believe that it is easy to plant fruit trees and let them effortlessly produce fruit. It is of course not that easy. Fruit trees need much more maintenance than common shade trees. Except for those in home gardens, such trees would not get the maintenance that they need. Most municipalities are unable to care for the trees that they already have. Shade trees in urban situations get pruned up for clearance above sidewalks and roadways. If fruit trees were pruned for such clearance, their fruit would be out of reach, and only promote the proliferation of rats and other vermin, and make messes below. Without adequate pruning, they would break apart from the weight of their fruit, and languish with disease. Spraying with pesticides to compensate for proliferating diseases and pests would be very unpopular in urban settings. Residents of both the San Jose and Los Angeles regions ask me about this often. I can only recommend fruit trees for private home gardens, where they can get the attention they need, and do not need to be pruned up high. (Some of the formerly suburban neighborhoods have nice parkstrips that can accommodate small fruit trees.)
    It would be nice if there were more people who live in cities who know a bit about horticulture, and could take care of such fruit and vegetable production. Cities are expensive places to live. Professional horticulturists do not earn enough to live in such cities. It is ironic that the region of San Jose used to be famous for stine fruit orchards, as well as pome fruits and even English walnuts, and some of the region near Los Angeles grew significant citrus orchards.

    • I agree in that we are disjointed in how cities/urban areas actually run, given demands of constituents, which are largely anthropocentric (if not 95%+). Unfortunately, I did not do a good job expressing my thoughts on urban ecology and the challenges present in making the “fruits” of such work accessible to all – particularly those without (i.e. homeless community). All of the subject matter in this article is more relevant to those “with” than “withouts”. I share this because as much as a tree needs to be maintained a certain way to be relevant for harvesting fruit, they are not being managed with those living on the street in mind. They are managed for maintenance crews, vehicles, aesthetics of persons who own homes, and businesses in mind; also not managed very well for actual nature (aka “wild”) vs. “perceived nature” (aka museums). If we managed for urban “food forests” for persons in need, created such rooftop gardens as horticultural job training sites for unemployed, developed “track” programs that led to actual jobs from such experience, and (most important) provided a means for said persons to eventually own their own property, THEN we would be talking about EQUALITY. Until then, while important to advancing concepts and design, these are tantalizing thoughts and ideas for the “rich”. I am in close contact with homeless community in Ft Collins, and I can tell you that the City as a whole does very little to make such environments homeless friendly or provide empowerment opportunities for them as stakeholders. We have some of the most “NIMBYIST” thinking of anywhere I have lived.

      • Those are interesting observations as well. I did not consider those demographics. Although I live near the Santa Clara Valley, I happen to live just outside of it, in a small town surrounded by the redwood forests of the Santa Cruz Mountains. People here are a bit more proficient with growing food in their home gardens; but also, the homeless have more opportunities to grow food. Those with property even allow homeless to grow food on parts of their property if they like. The homeless grow small volumes of food in the forest. Also, the homeless are proficient with finding food in the forests, including fruit from abandoned fruit trees. Our Community is VERY (almost overly) accommodating of the homeless, because the homeless are so involved with the Community. If none of the homeless collect surplus fruit, those who own the fruit trees collect the fruit themselves and bring it to the homeless. (There are places that we all know to deliver it.) Sometimes we get so much that we need to can it. Sadly, the situation we have here would not likely operate so fluidly in a bigger town. You may want to see my other blog at Felton League. It is about the homeless society here, although I have been unable to write new articles for the past few months.

  4. I have noticed a mini-trend. Several condo complexes in the area have converted some of their tennis courts into raised garden beds. Many of these complexes are mostly seniors who would rather garden than wear out their joints playing tennis!

  5. Christine Lemieux

    Thanks for this great article. It is a win win situation. I hope it spreads around the globe!

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