Green roofs are now a mainstay of urban green infrastructure and a tool to promote sustainable urban development. A number of municipalities, including Toronto-where I live, now have bylaws or policies requiring green roofs on certain types of infrastructure. The rationale for these requirements is that green roofs provide direct energy savings, reduce albedo, reduce storm water runoff, and support other ecosystem functions and provide wildlife habitat. But it is these last two –the ecological benefits, though often touted, lack clear evidence. I attended an organized oral session on green roof biodiversity organized by Whittinghill, Starry and MacIvor, and it was clear from the presentations that people were excited by the opportunities for ecological research. More importantly, they made the case that we know so little about these systems, and research is desperately needed to guide policy –we simply need more ecologists working on this problem.
|Chicago City Hall green roof, adapted from Wikipedia (CC-BY-SA 3.0)|
I would argue strongly that urban systems, like green roofs, are understudied and that these systems are the very places that ecological concepts and theories can have relevance. My medical colleagues study human physiology or microbiology in order to cure sick people –their science has direct application to improving the world and human well being, and ecologists have the same opportunity. Like a sick patient, urban systems are where our science can have the greatest impact and can provide the most benefit. Urban systems are under direct management and provide ample opportunity to manipulate ecological patterns and processes in order to test theory and manage societal benefits.
Time to study cities!