ISLAND HOPPING
Green roofs are effectively islands in the sky. And like real islands are notoriously hard to colonise, especially for flightless species. But colonise they do, and new research shows how.
Until now, it wasn’t clear whether soil organisms such as springtails and mites were imported with building materials and plants during construction or if they arrived under their own steam. It turns out that many species are indeed brought in during construction, but that most of these non-specialists quickly die off in the harsh conditions.
“This means that green roof soil species must arrive via another method, such as by hitching lifts on birds or coming in the aerial plankton,” says Heather Rumble, a biologist at the University of Portsmouth.
Rumble recommends that the biodiversity of green roofs could be boosted further by seeding them with appropriate species in the first place.