Green roofs as a climate change adaptation strategy in cities: Evaluation of greenhouse gas emissions, substrate temperatures, and water balance in north-eastern Italy

Covering building rooftops with vegetation [green roofs (GR)] holds promise as a climate change adaptation strategy in cities through the provision of ecosystem services, such as, lowering building temperatures, reducing stormwater runoff, and reducing greenhouse gas (GHG) emissions. However, there is a need for more studies that quantify these potential ecosystem services and evaluate how they are impacted by design and management practices. This work aims to evaluate three selected ecosystem services (reduction of GHGs, cooling of the microclimate, and stormwater management) and how they are affected by abiotic and biotic components of their design and management—i.e., vegetation type, substrate depth, and irrigation regime. We sought to test this by comparing daytime GHG emissions (i.e., CO2, CH4, and N2O), daily substrate temperatures, and the water balance of 48 GR microcosms in north-eastern Italy during an entire year. Four vegetation types (Sedum spp., cold season grasses, warm season grasses, or wildflowers), two substrate depths (8 or 14 cm), and two irrigation levels (1 or 2 L m-2 day-1) were evaluated, for a total of 16 treatments with 3 replicates.