Very interesting study undertaken in several cities in Switzerland on the species growing on walls. The biodiversity of walls is of course very interesting to anyone involved in urban biodiversity.
The following is an summary translation of the survey.
“Action Walls – What city has the wall with the richest biodiversity?
old stone walls are a unique habitat and essential to the lives of many animals, especially reptiles and invertebrates, as well as many fungi, lichens, mosses and flowering plants. These walls, which are urban shelters and ecological networks have avery characteristic flora and fauna. However they are unfortunately threatened and endangered as renovation work and beautification can lead to the loss ofimportant features, including crevices, holes and cracks, which allow vegetation and invertebrates to flourish.. Such crucial features are important for the development and presence of wildlife and vegetation rich in species.
It would be interesting to have such a study undertaken in London. I know of studies of flood defence walls along the Thames, such as at Deptford Creek, and have seen the rich diversity of plants along walls abutting the Ravensbourne and the Quaggy. If you are interested in bryophytes and other species associated with walls, there are species lists for the Cities of Bern, Neuchatel, Lausanne and Geneva.
An excellent study.