Plant Functional Traits Predict Green Roof Ecosystem Services

Abstract

Plants make important contributions to the services provided by engineered ecosystems such as green roofs. Ecologists use plant species traits as generic predictors of geographical distribution, interactions with other species, and ecosystem functioning, but this approach has been little used to optimize engineered ecosystems. Four plant species traits (height, individual leaf area, specific leaf area, and leaf dry matter content) were evaluated as predictors of ecosystem properties and services in a modular green roof system planted with 21 species. Six indicators of ecosystem services, incorporating thermal, hydrological, water quality, and carbon sequestration functions, were predicted by the four plant traits directly or indirectly via their effects on aggregate ecosystem properties, including canopy density and albedo. Species average height and specific leaf area were the most useful traits, predicting several services via effects on canopy density or growth rate. This study demonstrates that easily measured plant traits can be used to select species to optimize green roof performance across multiple key services.

Community assembly on extensive green roofs: Effects of dispersal‐, abiotic‐ and biotic filtering on the spontaneous species‐ and functional diversity

“…Plant species traits were obtained from several databases (Table ) (Hintze et al., ; Kattge et al., ; Kleyer et al., ; Kühn, Durka, & Klotz, ) and supplemented with estimates based on expert judgment (field observations, related species traits) for some species and complexes. The selection of plant traits was based on their relevance in the different filter processes, their impact on green roof functioning (Lundholm, Tran, & Gebert, ; Xie, Lundholm, & Macivor, ), their presence in the LHS scheme (height−seed mass−specific leaf area) of Westoby () and their availability for the majority of the species in this study. The gathered seed‐related traits such as seed longevity index, seed mass, D3 anemochory ranking index (related to the seed terminal velocity) and seed releasing height can be of interest for dispersal and connectivity.…”

Nature-based Solutions: New Influence for Environmental Management and Research in Europe

“…Similarly, rain gardens designed to manage storm water runoff that pay little reference to what plants are used and to other ES, fall short of NBS. In contrast, within an urban planning approach at the city scale, a range of species could be selected for green roofs or walls based on their biogeography and key functional traits (Lundholm et al 2015), which would address multiple goals such as cooling during summer, storm water capture, pollution abatement, increased human well-being, biodiversity enhancement, and better resilience to future hazards, while adopting adequate governance to properly tackle the issue at city scale (figure 2, p. 247). Such approaches would fit the NBS term.…”

Plant species richness enhances nitrogen retention in green roof plots

“…They hypothesized that structural complexity was more important than diversity for water retention (Dunnett et al, 2008). Lundholm et al (2015) predicted variation in 6 different green roofderived ecosystem services including water and nutrient retention, based on plant functional characteristics (height, individual leaf area, specific leaf area, and leaf dry matter content). In that study, plant growth rate was correlated to a one-time measurement of soil N and P concentrations, and this was taken as an indication that plant uptake of nutrients could reduce nutrient leaching; however a direct effect of species richness was not shown (Lundholm 2015; Lundholm et al 2015).…”

“…Lundholm et al (2015) predicted variation in 6 different green roofderived ecosystem services including water and nutrient retention, based on plant functional characteristics (height, individual leaf area, specific leaf area, and leaf dry matter content). In that study, plant growth rate was correlated to a one-time measurement of soil N and P concentrations, and this was taken as an indication that plant uptake of nutrients could reduce nutrient leaching; however a direct effect of species richness was not shown (Lundholm 2015; Lundholm et al 2015). None of these studies measured nutrient retention vs. nutrient leaching directly, which is an important urban ecosystem service to help prevent eutrophication in downstream waterways (Smith et al 1999).…”