Browsing by Author "Liao, Wenfei"

Urbanisation has caused many environmental problems, such as air pollution and the loss of biodiversity. One way to mitigate these problems is to expand green spaces. Roofs, as the last frontier, could be made full use of. Green roofs have become a hot topic in recent years. In this study, I investigated the ability of green roofs to support urban biodiversity by conducting a literature review, and then I sought the criteria for biodiversity roofs under Finnish conditions by interviewing ecologists. My research questions in this study were 1) What kinds of habitats could be 'ideal ecosystems' to be mimicked on biodiversity roofs in Finland; 2) which plant species could exist on roofs and whether they contribute to biodiversity; 3) what kinds of substrates support the biodiversity on roofs; 4) whether green roofs support faunal diversity and what faunal taxa could exist on roofs; 5) if and how roof structural characteristics influence roof biodiversity; 6) what kinds of management are practiced on biodiversity roofs; 7) what are people s attitudes towards or perceptions of biodiversity roofs in general. In this study, I conduct that 1) Sunny dry habitats, such as meadows and tundra, can be regarded as 'model ecosystems' for biodiversity roofs in the Finnish context. 2) Substrate heterogeneity is a key to biodiversity on green roofs. Different materials and different combinations of materials could be applied on the same roof to mimic diverse types of soil types in the most biodiverse Finnish ecosystems. 3) Native species from the model ecosystems are ideal plants for biodiversity roofs. Combining multiple greening methods on the same roof can be a solution to achieve 'instant greening effects' with only native species. 4) An ideal biodiversity roof in the Finnish context could support birds, bats, and invertebrates, such as spiders. To attract and support fauna, a roof needs a diverse plant community, as well as extra elements, such as deadwood. 5) Roof structural characteristics (i.e. roof height, size, slope, direction, location, and age) impact biodiversity by determining the accessibility to and the dispersal of flora and fauna, as well as microclimates on roofs. 6) Management, such as irrigation, might help biodiversity at least for newly established biodiversity roofs, but biodiversity roofs aim at being self-sustaining eventually. 7) People have generally positive attitudes towards green roofs, but their willingness to actually install a biodiversity roof is influenced by other issues, such as the financial cost and roof safety.