Abstract
Green roofs have been proposed as a significant method of “renaturing” the city, mitigating the urban heat island effect and controlling storm water movement. Plant growth on green roofs affects the environmental performance of the roof. Thus, it is important to examine which parameters influence this growth. Green roofs in the Mediterranean region, due to the climatic specificities of the area, have been a challenge. What types of plants are appropriate, how green roofs should be constructed and other related topics have concerned scientists in the recent years. The aim of this pilot study was to explore the growth of five plants—Sedum sediforme, Drosanthemum floribundum and Lampranthus spectabilis, Medicago arborea, and Lavandula angustifolia—on a pilot Mediterranean green roof in relation to substrate depth, organic content of substrate and type of green roof (open and modular). Data were analyzed using multiple regression with Analysis of Variance. The results indicated that substrate depth, type of green roof and substrate organic content are not significantly important parameters affecting the growth of plants and cannot predict plant performance by themselves. A main insight arising from this study is that plant communities and interspecies relations should be examined more closely in future green roof research as they may affect the impact of selected parameters on plant growth on Mediterranean green roofs. Furthermore, although the type of the green roof—open or modular—could not be directly associated with plant performance, it may be worth examining its impact on plant community performance in future studies.
Highlights
Cities continue to grow and to attract an increasing number of people; at present, cities house more than half of the global human population
The statistical analysis demonstrated that substrate depth was not an important parameter affecting Growth Index (GI)
Observations from the analysis indicate that substrate depth did not impact the growth of D. floribundum
Summary
Cities continue to grow and to attract an increasing number of people; at present, cities house more than half of the global human population. The environmental benefits of green roofs have been the focus of many studies in the last decades (indicatively see Oberndorfer et al, 2007; Nagase and Dunnett, 2012; Berardi et al, 2014; Gong et al, 2021) These benefits include amongst others energy efficiency of buildings, storm water control, enhancement of microclimate and amelioration of the urban heat island effect, cleaner air, filtering water, increased biodiversity in cities, psychological benefits and aesthetic enhancement of urban landscapes. Each of these themes has attracted different levels of interest, while overall, researchers’ interest in green roofs has increased over time (Liu et al, 2021)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
