Growing Trends in Hybridized Nature

By Timothy Beatley

Singapore's Gardens by the Bay is 250 acres of reclaimed land turned sustainable urban oasis. Three waterfront gardens feature conservatories, a flower market, an event space, a children's garden, and, towering above it all, 18 "supertrees." These supertrees look like trees and perform many of the same functions — they cool and shade, provide habitat, capture the sun's rays — but are like no trees known in the natural world. They are up to 160 feet each of plant life fused with steel, concrete, and photovoltaic panels. And they represent a growing trend in urban nature: a blending between green infrastructure and sustainable technology.

Biology and technology together

We will always want actual living nature in cities — and we will need to keep finding increasingly clever ways to insert it. In the case of the supertrees, plants — orchids, ferns, epiphytes — grow on "living skin" without soil (the plants are clipped to the exterior metal framing). And there are many plants: more than 162,500 of them, according to the Gardens by the Bay's website (gardensbythebay.com), and more than 200 species. Each of these concrete and metal trees harbors a lot of life and is itself a vertical garden. They also collect rainwater, are solar powered, and provide venting for nearby conservatories.

The supertrees seem to hold out the possibility that these kinds of hybrid, engineered forms of nature might eventually be an important supplement to the ecological services provided by trees and more traditional green elements. We are already seeing commercial companies market such ideas, like the CityTree now being sold by the German start-up Green City Solutions. This product is essentially a movable moss wall that filters urban air and doubles as a piece of furniture. Reportedly, each CityTree installation provides the air quality benefits of 275 trees. Like the supertrees, it also adds a visual element of green to gray urban settings.

Other ideas are percolating in the design and planning world. Mitchell Joachim and his firm Terraform One are working on a variety of designed structures that equally merge the natural with the less than natural to accomplish a variety of things. "Biology is Technology" is Joachim's motto, and his ideas include growing new building materials like growing mushrooms — indeed, by employing mycelium, the vegetated element of fungus (more on that in a bit). He also aims to update the ancient art of "pleaching," or growing and training vines and trees to make new shapes and forms. It should be possible to grow houses in the future, and they are prototyping methods for doing this, he says.

"These homes make no distinction between landscape and house," he recently told an audience at Kent State University. "They're one and the same." It is the ultimate form of living architecture and true immersion in nature, he says.

This idea of "growing" homes and buildings seems a little farfetched, but this is an idea the Defense Advanced Research Projects Agency, within the U.S. Department of Defense, has been working on through its Engineered Living Materials program. The vision is of living structures capable of self-healing and self-repair. Biomaterials company Ecovative Design was recently awarded a $9 million grant from DARPA to develop such growing systems. They're already doing this commercially through an innovative growing system using fungal mycelia (the roots of mushrooms). I ordered a couple of sample wall tiles and was impressed when they arrived: There was an impressive heft to these fully biodegradable panels, made the more remarkable given that they were "grown."

For a closer look at Singapore's Gardens by the Bay — and its innovative feat of hybridized nature, the supertrees grove — go to youtu.be/5UhnuddcAsE. "Supertrees, Singapore" by Rod Waddington, Flickr (CC BY-SA 2.0).

Habitat-restoring structures

One of the most visually striking prototypes Mitchell Joachim presented at Kent State University was the "Cricket House." The structure serves two functions: It's both an emergency shelter and a cricket grow house, a potential food source he argues could serve as a more environmentally friendly form of protein. Compared with conventional raising of cattle or chicken, he says, the water consumption and carbon footprint from raising crickets would be a fraction of what is usually required. These units "could be modular and stacked and brought to communities in need," he says.

Yet another interesting project under development is a new double-skinned building facade for a structure in the Soho neighborhood of New York that would include a habitat for monarch butterflies. The design of this skin aims to ensure human comfort for occupants of the building, along with the other usual architectural goals, and also serve as a "butterfly sanctuary and vertical meadow." This reminds me of William McDonough's design for the Ferrer Research and Development Center in Barcelona (which is not yet built) that would include a lobby with a butterfly nursery. Fully replacing the habitat lost from cities and built structures will likely require more of these kinds of blending of nature and design. More cities are implementing some form of a green area ratio, requiring that ground-level nature sacrificed for buildings be offset by nature in the vertical realm. One new building in Singapore, Oasia Hotel Downtown, replaces ground-level nature by 900 percent; most of its exterior facade is covered in growing plants.

There is, of course, an important biophilic dimension to these hybridized forms of urban nature. The Singapore trees have a monumental feeling, and they are beautiful in part because they remind us of real trees. The supertrees seem to touch a deep biophilic chord, connecting to our innate attraction to nature, but not every building or urban structure will be able to accomplish that; this is the challenge urban designers will face when merging organic, growing material with structural elements.

And, of course, we must ensure that building supertrees doesn't divert energy and resources away from investing in real nature. In Singapore, that has not happened so far: The city continues to plant trees, and to expand its urban canopy in many creative ways. Hybridized nature is a meaningful supplement — and why not view every designed object in the city as a chance to meld, or fuse, or creatively integrate some form of nature into our concrete jungles?

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