The growth and survival of plants in urban green roofs in a dry climate.
Green roofs as one of the components of water-sensitive urban design have become widely used in recent years. This paper describes performance monitoring of four prototype-scale experimental green roofs in a northern suburb of Adelaide, South Australia, undertaken over a 1-year period. Four species of indigenous Australian ground cover and grass species comprising Carpobrotus rossii, Lomandra longifolia 'Tanika,' Dianella caerula 'Breeze' and Myoporum parvifolium were planted in extensive and intensive green roof configurations using two different growing media. The first medium consisted of crushed brick, scoria, coir fibre and composted organics while the second comprised scoria, composted pine bark and hydro-cell flakes. Plant growth indices including vertical and horizontal growth rate, leaf succulence, shoot and root biomasses, water use efficiency and irrigation regimes were studied during a 12-month period. The results showed that the succulent species, C. rossii, can best tolerate the hot, dry summer conditions of South Australia, and this species showed a 100% survival rate and had the maximum horizontal growth rate, leaf succulence, shoot biomass and water use efficiency. All of the plants in the intensive green roofs with the crushed brick mix media survived during the term of this study. It was shown that stormwater can be used as a source of irrigation water for green roofs during 8 months of the year in Adelaide. However, supplementary irrigation is required for some of the plants over a full annual cycle.
Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, Adelaide, Australia. Electronic address: razmy005@mymail.unisa.edu.au.
M
M
Razzaghmanesh
Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, Adelaide, Australia.
S
S
Beecham
Department of Horticulture and Landscape, Ferdowsi University of Mashhad, Iran.
F
F
Kazemi
D002947:Cities; D002980:Climate; D003247:Conservation of Natural Resources / Q000379:methods*; D005160:Facility Design and Construction / Q000379:methods*; D063245:Plant Development; D010944:Plants; D013021:South Australia
Green roof; Plant growth index; Stormwater; Water use efficiency; Water-sensitive urban design