Storing Carbon in Green Roofs: Above- and Below-Ground Biomass of Blue Grama and White Stonecrop

While green roofs are often utilized for energy savings and heat island mitigation, this technology hasn’t been extensively promoted for its ability to mitigate climate change. Green roofs have the potential to significantly reduce the amount of carbon dioxide in the atmosphere through carbon sequestration. This study focused on two low maintenance plant species commonly found on extensive green roof systems, blue grama (Bouteloua gracilis) and white stonecrop (Sedum album). The main objective was to quantify the above- and below-ground biomass of those two species to provide greater understanding of their carbon sequestration potential. If increased storage of carbon and organic matter in green roof substrate is the desired outcome, then blue grama is a more valuable species than white stonecrop. Results showed that least square means of above-ground biomass of blue grama (21.29±1.66g) was more than twice as great as that of white stonecrop (6.40±1.66g, Table 2). Similarly, blue grama root biomass was more than twice as great (14.84±1.32g) as that for white stonecrop (6.83±1.32g)