Carbon dioxide sequestration capability of the Botanical Garden of Rome: environmental and economic benefits

The recent decades have seen large increases in the extent of urban and built-up land use. It is predicted that 60%-90% of the world population will live in cities in 2030. The loss of green areas (urban parks, avenue tree-lines, woods, hedges, private gardens and public green spaces) as a result of the increasing urbanization is a serious threat to the overall biodiversity and calls for considerations of their role, provision and management. Urban green spaces provide ecosystem services, such as offsetting carbon emission, removing air pollution and reducing noise. In particular, green areas act as a sink for atmospheric carbon dioxide (CO2) via photosynthesis and storing excess carbon as biomass. Moreover, they are places for physical recreation which have positive effects on human health. When exposed to green areas people show a greater well-being and physical and psychological benefits. Among the urban green areas, the Botanical Gardens have a key role in biodiversity conservation. Nevertheless, they provide environmental benefits contributing to air amelioration quality. In this context, we analyzed the CO2 sequestration capability of plant collections growing in the Botanical Garden of Rome and their influence on microclimate. The Botanical Garden covers an area of 12 ha in the city centre, between Lungara Street and the Gianicolo hill. The lower area is enriched with tree species, including many palms, while the hill is occupied by the ferns collection, Bamboos, Rose garden, Australian species, Japanese garden, Mediterranean woods and Conifers collection. The results suggest appropriate policy interventions in order to facilitate future urban designs enhancing the environmental and social benefits from green areas.