title: Developing resilient green roofs in a dry climate.
abstract: Living roofs are an emerging green infrastructure technology that can potentially be used to ameliorate both climate change and urban heat island effects. There is not much information regarding the design of green roofs for dry climates and so the aim of this study was to develop low maintenance and unfertilized green roofs for a dry climate. This paper describes the effects of four important elements of green roofs namely slope, depth, growing media and plant species and their possible interactions in terms of plant growth responses in a dry climate. Sixteen medium-scale green roofs were set up and monitored during a one year period. This experiment consisted of twelve vegetated platforms and four non-vegetated platforms as controls. The design for the experiment was a split-split-plot design in which the factors Slope (1° and 25°) and Depth (100mm, 300 mm) were randomized to the platforms (main plots). Root depth and volume, average height of plants, final dry biomass and ground cover, relative growth rate, final dry shoot-root ratio, water use efficiency and leaf succulence were studied during a twelve month period. The results showed little growth of the plants in media type A, whilst the growth was significant in both media types B and C. On average, a 90% survival rate of plants was observed. Also the growth indices indicated that some plants can grow efficiently in the harsh environment created by green roofs in a dry climate. The root growth pattern showed that retained water in the drainage layer is an alternative source of water for plants. It was also shown that stormwater can be used as a source of irrigation water for green roofs during six months of the year at the study site. In summary, mild sloping intensive systems containing media type C and planted with either Chrysocephalum apiculatum or Disphyma crassifolium showed the best performance.
authors.affiliation: Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, Adelaide, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Razzaghmanesh
authors.affiliation: Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, Adelaide, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Beecham
authors.affiliation: Phenomics and Bioinformatics Research Centre, School of Information Technology and Mathematical Sciences, University of South Australia, Adelaide, Australia; The Australian Centre for Plant Functional Genomics, Waite Campus, University of Adelaide, Urrbrae, Australia.
authors.forename: C J
authors.initials: CJ
authors.lastname: Brien
mesh_terms: D002980:Climate; D057231:Climate Change; D003247:Conservation of Natural Resources / Q000379:methods*; D004777:Environment; D005160:Facility Design and Construction / Q000379:methods*; D063245:Plant Development; D010944:Plants
keywords: Green roof; Plant growth index; Resilient cities; Stormwater; Water sensitive urban design