One of the most cutting-edge directions of green roofs involves creating habitats for biodiversity. Most designers are familiar with gardening for wildlife on the ground in suburban and rural gardens, but many haven’t thought about inviting insects and wildlife into the urban roofs context.
Closer examination of urban environments reveals an entourage of insects and native bees already living there along with a multitude of tenacious and persistent plants, which work their way into sidewalk cracks, brick walls, and chimney tops. There are peregrine falcons roosting on skyline parapets, flushes of summer butterflies on flowers in sidewalk beds, and bird songs in the early mornings. Nature is in the city, and we can create more footholds, nooks, and niches for wildlife and instigate more habitats on green roofs with intentional design.
With the growing acceptance of rooftops as the new landscape frontier, designers have a unique opportunity to bring nature back into the city, but establishing natural habitats in urban environments is no slam-dunk affair. Creating a functioning living system of plants and soil from scratch requires considerable research and reinvention. The exciting thing is we have the option to design systems that function ecologically and encourage biodiversity with the added bonus of specifying the types of habitats we wish to foster and for whom.
In his book Last Child in the Woods, Richard Louv substantiated the position for more green roofs. After examining the connection between nature and humans, he concluded that urban dwellers are nature starved and that many city kids now experience what he describes as nature-deficit disorder. His studies revealed that urban children and adults spend more time engaged with technology than getting their hands dirty exploring a creek bed. Louv also described the decline of natural world exploration in urban school curriculums, claiming that students are taught more about genetic engineering than entomology.
Traditionally, the history of landscape design has been more about conquering or taming nature than about embracing it. However, we need more animals and green space in our cities to be healthy and happy. Green roof designers have a unique opportunity to lead the way in making this happen.
One way to accomplish this goal is to learn methods for allowing nature to seed itself and thrive in urban areas, all the while encouraging the intertwining of humans and nature. This new age of active coexistence could be framed as an age of integration, a term we have been using in our work to describe the premise that we are nature, and figuring out how to design from there rather than from the notion that we are separate. Shifting this basic perspective allows for new and lasting design solutions to be developed.