Only cooling and saving water? Effects of rainwater management measures on biodiversity: a meta-analysis
Fostering adaptation to the ongoing global warming is a main challenge of urban planning and design. Crucial techniques for ecological design and engineering are rainwater management measures (RWM measures: ponds, swales, green roofs, green façades or rain gardens). Beyond handling urban rainwater, these measures can provide a wide range of ecosystem services to city dwellers, like enhancing the urban landscape's aesthetics and life quality, or cooling down buildings in summer while keeping them warm in winter. We study the effects of different RWM measures on the biodiversity through their design and management in order to enhance biodiversity-friendliness of RWM measures and elaborate guidelines for planners and architects. We reviewed the literature concerning biodiversity and RWM measures to collect data on floristic and faunistic inventories by RWM measures, such as different design parameters and management options. Indicators have been defined to analyse the biodiversity by RWM measures. Data on biodiversity indicators and RWM measured characteristics were systematically reported into a common database and unified for statistical analysis. Here we present our first results for green roofs, which show that RWM measures provide habitats for a wide range of animal and plant species, among them many neophyte species and thus represent novel urban ecosystems. There is first evidence, that RWM measures can also play an important role in urban biodiversity conservation since they host rare or endangered species. The design and management options of green roofs strongly influence the number and quality of habitats and thus have an impact on other biodiversity indicators such as alpha-diversity. Our results help to define a first frame for guidelines to help rainwater management and urban planning actors implement and manage more biodiversity friendly RWM measures and to enhance the associated ecosystem services.
Pille, L. and Saeumel, I. (2017). Only cooling and saving water? Effects of rainwater management measures on biodiversity: a meta-analysis. Acta Hortic. 1189, 481-486
urban rainwater management measures, biodiversity, green roof, green façade, swale, pond