Understanding the Benefits from Green Areas in Rome: The Role of Evergreen and Deciduous Species in Carbon Dioxide Sequestration Capability

摘要

Urban areas are a major source of anthropogenic carbon dioxide (CO_( 2 ) ) emissions because of road traffic and local heating with natural gas, oil or coal. Rome is among the largest European cities (129,000 ha) with a large volume of green areas (69.6% of the total Municipality area). The CO _( 2 ) sequestration (CS) capability for the greenery extending for about 300 km ~( 2 ) inside the area delimited by the Great Ring Road (GRA) in Rome was calculated combining satellite data with CS data measured in the field. Data from Sentinel-2 were collected and the Normalized Difference Vegetation Index (NDVI) was computed on a pixel-base. Three plant classes homogeneous in terms of annual NDVI profile were identified: deciduous trees (DT), evergreen trees (ET) and meadows (M) covering an area of 14,142.027 ha within the GRA, of which M had the highest percentage (48%), followed by DT (27%) and ET (25%). CS ranged from 428,241 , 492.9 T ons CO _( 2 ) year ~( -1 ) (ET) to 263,072 , 460.6 Tons CO _( 2 ) year ~( -1 ) (M). The total CS of the greenery inside the GRA was 1049,490,355.4 Tons CO _( 2 ) year ~( -1 ) resulting in an annual economic value of $772,424,901.6/ha. The CO _( 2 ) sequestration capability of the considered plant classes could be incorporated into the national greenhouse gas emission budget to calculate the contribution of CO _( 2 ) sequestration to the economy of Rome.