A Microbial View of Planning

By Timothy Beatley

In 1851 an amateur microscopist by the name of Agnes Catlow published a fascinating, and at the time eye-opening, book called Drops of Water, exploring the little creatures found in typical droplets of water. We sometimes forget how much of the world's life takes place in this microscopic realm, and that there are many ways (most of them we don't understand very well) in which these biota affect our basic well-being and health.

I recently interviewed Rob Dunn, a biologist and writer at North Carolina State University, who has been an enthusiastic and intrepid explorer of this hidden world. He is the author of several books, including the highly readable The Wild Life of Our Bodies. "It has become more and more clear to me through time," Dunn told me, "that we tend to spend the least time studying those things that are immediate to us. Certainly it's true we don't know very much about the Amazon, but it's also true that we don't know very much about our houses and backyards." These realms of nearby nature have been "systematically ignored," Dunn says. Yet it is a world that has many implications for cities and for planning, and undoubtedly many we don't fully understand.

To immerse oneself in Dunn's world (or Catlow's) is to profoundly adjust our conception of the world. Biodiversity is all around us in great abundance — we are hardly separated from nature, as we often feel we are, when it thrives in our bellybuttons, armpits, and hair.

And indeed these many microbial co-inhabitants provide us with many benefits that we are just beginning to appreciate. Our typical view of microbes has been rather indiscriminant — and all are generally lumped in the category of "bad" and seen as in need of killing (as we attempt to do with antibiotics). Yet increasingly we know that many microorganisms are important to our health.

Dunn points to a recent Finnish study showing that the biodiversity on our skin and bodies depends on proximity to nature and green spaces; and the greater the bio-diversity on the body, the less likely one will be subject to allergies, and perhaps immune disorders. Dunn points, too, to our growing understanding of the essential positive value of gut microbes.

At home with germs

Now, regular people are engaged in learning about the everyday organisms around us, thanks to Dunn and other applied biologists. In one project Dunn and colleagues asked home owners to help collect all the arthropods in 50 homes in Raleigh, yielding first-ever information about the critters co-occupying our homes (including a species of parasitoid wasp found in almost every Raleigh residence).

A more ambitious project is the Wild Life of Our Homes, involving some 1,600 homes where residents take swab samples of spaces, then send them to Dunn and his lab to analyze and identify the microbial life found there. "If we're really going to engage the public in what science is, how one does science, but also in the joy of making a discovery, these species [all around us] are perfect for that."

There is even evidence that proximity to parks and natural areas — in homes and buildings (and climates) where windows can be left open — helps to deliver a microbial cocktail that is highly beneficial to us. Dunn speculates on the future role of small parks, even nearby trees, as important microbial reservoirs (in a way he similarly has written about the human appendix). Although we are still unsure what this healthy microbe mix consists of (and in fact there are many thousands of species still to be discovered and understood), the promise is great.

Learning the names of animalcules

Finding ways to give adequate attention to the small worlds and creatures around us is a needed first step in planning. Agnes Catlow and others of her day referred to the exotic animal life they saw through their microscopes by the charming word animalcules, which perhaps better conveys the intrigue and fascination value of this realm of life that many just think of as yucky. (Dunn agrees with me that this is a better word, and one we should perhaps resurrect.)

I'm reminded of another book from Catlow's era, by the well-known British naturalist Philip Henry Gosse: Evenings at the Microscope (1859). The title evokes an image, but as of yet, there are not many families spending time exploring the fascinating microbial life around them and the microscope is hardly a standard piece of home entertainment equipment, as essential as a Game Boy or Wii.

A larger lesson is the potential in understanding the broader lives and life forms sharing the spaces around us in cities, microscopic or not, and here biologists like Dunn have much to teach planners. Dunn is intrigued with the Cliff Theory of Cities — that modern cities, whether through conscious design or inborn preference, tend to emulate cliff habitats (a theory developed first by Canadian ecologist Douglas Larson). Many of the species that co-inhabit cities with us, from pigeons to peregrine falcons to dandelions, are also indigenous to such habitats, and Dunn believes they may provide insights about what other life forms might beneficially inhabit these environments and thus be encouraged.

For my part, I am planning to redouble my efforts to learn about and include the microscopic world in my writing, research, and worldview. So much nature and biodiversity is around us in cities, and it would be wise to expand our conceptions of place and community to include them. Planners and planning academicians should begin to work together with biologists in better understanding this realm and in designing and managing built environments to ensure both human and ecosystem health.

Image: Catlow's 1851 book showed that mundane water droplets actually teemed with life. From Drops of Water.

Timothy Beatley is the Teresa Heinz Professor of Sustainable Communities at the University of Virginia, where he directs the Biophilic Cities Project.