Following last month’s blog about the world green roof congress, I promised the second revelation that will influence how I think about green roofing. From the macro to the micro, this inspiration came from Heather Bumble’s research into the micro-organisms living in green roof substrates.
Green roofs are gaining popularity as a way to help prevent species loss and support ecosystems in urban areas. Although habitat features like logs and stones with long flowering plants and varied substrate depth are known to encourage invertebrates, often ubiquitous sedum roofs are assumed to have some of these benefits too to a lesser degree.
After studying microscopic creatures like springtails and mites that live in soil and form an essential part of a healthy ecosystem, Heather recorded that extensive sedum roofs bring almost none of these organisms to the roof when installed, and do not support sustainable communities when they arrive from elsewhere.
This shows the need for focused assessment of what ecological goals are expected from a green roof and careful design accordingly. We will be keeping up with developments in this area and making sure our product development follows mite-friendly advice.