Excerpt from this story from The Revelator:
Last summer I took advantage of my break from teaching by enjoying long, daily walks around my neighborhood. I indulged my mind and body in the blueness, stillness, and leafiness that is North Carolina in June and July. It’s truly astounding how many leaves a willow oak can cram into one tiny piece of sky.
On my walks, the yard of one house stuck out. It was unlike any yard I’ve seen around my city or in any of the other cities in the United States, Canada, and Australia where I’ve lived. It is a forest yard. Nearly a dozen large trees are interspersed amid a dense stand of saplings and shrubs. That summer, leaf litter covered the ground. The top of the house was only visible if I craned my neck to see down the paved driveway, itself narrowing and crumbling as roots, lichens, and fungi worked their inexorable magic.
Depending on your perspective, the house with the forest yard could be seen either as an eyesore — and the scariest place to trick-or-treat — or, as in my case, the most splendid place imaginable.
At this point, I should probably mention that I’m an urban ecologist and that the forest yard makes my heart flutter at the possibility and hope of nature in cities.
I looked at aerial images for the area, and they revealed that the trees around that home, which haven’t been actively “managed,” are about 50 years old. Over that time the forest yard has accumulated a bewildering array of species and ecological interactions. Its tulip poplars, walnuts, cedars, redbuds, pines, and willow oaks have soaked up the atmosphere’s carbon dioxide and turned it into much-needed habitat for wildlife: butterflies, bees, and other insects; lizards, snakes, and turtles; frogs and toads; birds; and mammals. It’s home to a multitude of soil invertebrates and fungi that keep the business side of an ecosystem — aka decomposition — going. All the species that share this shady third-of-an-acre lot are intertwined in a complex tangle of relationships that keeps them fed and feeding on one another, interdependent to varying degrees for their life and livelihood.
And all of this exists amidst a matrix of roads, single-family and multiplex housing, commercial plazas, light industry, and high rises that make up a medium-sized city in the Southeast. The forest yard is a little island of nature in a nearly lifeless sea of concrete, asphalt and lawn.
But, to my inexhaustible surprise, that sea of concrete, asphalt, and lawn is not as empty as we tend to assume. Very far from it. Places of dense human habitation are also where many species reside, including some that are threatened. A recent analysis of the birds and plants that occur in 147 cities across the globe revealed that the sampled cities were home to 2,041 bird species — about one-fifth of Earth’s total avian diversity — and 14,240 plant species. These include 36 bird and 65 plant species threatened with global extinction.
To get a better idea of just how much of the urban biodiversity iceberg lies below the surface of our awareness, consider this: Last year participants in the City Nature Challenge made nearly 1.9 million observations in 480 cities, with the residents of the La Paz metropolitan area in Bolivia recording the high score of 5,320 species.
Add to this the estimate that we share our homes and yards with an average of 9,000 species of fungi and bacteria and you’ll begin to suspect, as I do, that cities are in fact incredibly biodiverse. And it’s not just the all-too-rare forest yard: Scientific evidence shows that the more people you find in a place, the more types of birds, mammals, and plants you’ll find there too.
So why don’t we see it that way? Why do we perceive our urban centers as unworthy and undeserving of our conservation efforts and attention?