Estimating CO2 balance through the Life Cycle Assessment prism: A case – Study in an urban park

In a context of progressive urbanization, urban parks can play a pivotal role in carbon sequestration and stock. The study employs Life Cycle Assessment (LCA) to evaluate CO2e (carbon dioxide equivalent) emissions and removal by plants and soil in different urban green typologies, namely afforested areas, tree rows, social allotments, lawns, hedges, referring to a life span of 50 years. The present study aims to evaluate the carbon balance connected with planning, planting, and maintaining an urban park, the Parco Nord Milano (PNM), a green area located in the metropolitan area of Milan, Italy. The different emission data took into consideration planting and maintenance interventions, including the effects of equipment and vehicle choices, main operational activities, and the fate of vegetal residue from pruning, shrub and tree removal, and lawn mowing. The best performances in terms of CO2e balance per surface unit was obtained with tree rows and afforested area typologies (- 789 and – 527 Mg CO2e ha−1 50yrs-1, respectively), while the hedges showed the worst CO2e balance, (+ 176 Mg CO2e ha−1 50yrs-1). Different planting options, different pruning or thinning intensities or species selection can change this balance. In addition, converting residues from removed trees into wood products can improve the storage of CO2 for long periods. LCA has proved to be an effective tool to support the planning and maintenance of urban parks and the types considered. However, rational planning must also have to take into account user preferences and needs, and which ecosystem services can be maximized to ensure a better quality of life.