Native plant evaluation and green roof performance : the influence of composition and richness on ecosystem functions

Abstract

Despite the variety of green roof benefits at least partly dependent on the vegetation layer, the influence of plant composition is often ignored, with only limited types of vegetation commonly used. The goal of this thesis is to explore how the composition of a green roof's vegetation layer can affect, and might be used to improve, green roof functioning in a maritime setting, and to assess the potential of native coastal barren species by examining the relationship between species composition, functional group composition, and functional group richness, and: 1) green roof vegetation traits; and 2) green roof environmental functions. Grass and tall forb species had the most favoured canopy characteristics (e.g., increased cover). The inclusion of grasses, and tall forbs or succulents, also optimized temperature moderation and stormwater management functions. Further, most native species showed comparable or more favourable traits and performance compared to the common green roof species tested.