The growing popularity of living walls, living roofs and re-vegetation of urban areas is not only good for our mental and physical well-being1, but it also means we can be a part of reversing a decades-old trend that threatens the basic ecosystems undergirding our modern way of life.
The life we are accustomed to is entirely dependent upon natural systems working in the background to clean our air, fix nitrogen in the soil, filter our water, maintain vegetation, produce our food and keep pests under control2. These systems have evolved over billions of years to become adept at these functions, not only for their own survival but for the survival of other species that they depend on. However, there are many signs that we are causing an undue amount of stress to these natural systems.
Consider, for example, the recent proliferation of Colony Collapse Disorder. Healthy bee populations are at the heart of how farmers produce a wide variety of foods, including: almonds, apples, beans, pumpkins and many kinds of berries. While scientists have not yet determined the exact cause of Colony Collapse Disorder, a leading theory is the changes they have noted in bee habitats.3
Habitat loss is identified as the main threat to 85 percent of threatened or endangered species on the International Union of Conservation of Nature and Natural Resources Red List. According to the World Wild Fund for Nature, the expansion of agricultural land, intensive harvesting of timber and overgrazing are contributing to this problem. Each of the species impacted by these losses play an important role in the ecosystems we depend on every single day. While a single living wall itself can’t make up for the broad benefits of acres of forest, the larger trend of introducing more vegetation into our everyday life is a step toward bringing organism populations back to our urban and suburban areas. This trend also shows that we are starting to truly acknowledge the cost of ecosystem loss to our society.
Exterior living walls increase the surface area and height above grade that is available to organisms for shelter, and a wide variety of plant material means shelter for insects, birds and small mammals. Exterior vegetation also collects moisture and water in the early morning and after rainfall, and, in doing so, lowers the temperature of the microclimate and provides a haven for moisture-seeking organisms. Living walls can be coupled with natural landscaping, exterior water features and passive storm water strategies to further increase their beneficial impact.
While it is going to require larger policy changes towards land use, energy use and transportation trends to fully reverse the damage that we have already done, these living structures allow us to do something about this impending problem on the scale of an individual project. When is the last time you looked out of a window in the city and saw a hummingbird? Or a hawk? Wouldn’t it be a beautiful future if we were able to bring these and other species back to our cities and towns?