Urban Ecosystem Services – Potential of Urban Green Cover (Tbilisi case study)

Abstract

The beneficial features of green spaces, urban parks, and green infrastructure in big cities are well recognized. Trees absorb pollutants from the air, regulate temperature, support biodiversity, and maintain ecological equilibrium in urban areas. However, the extent of these benefits and the volume of ecosystem services provided by urban parks are still not fully understood. The aim of our study was to determine the types of ecosystem services provided by urban parks and the green cover of urban cemeteries, evaluate these services, and identify their roles in improving the environmental and ecological status of the city. In 2018 and 2021, we studied two urban parks and one cemetery in Tbilisi using the modeling platforms i-Tree Eco and i-Tree Canopy of the USDA Forest Service. The research revealed that the green infrastructure of Tbilisi's "Red Park," "Expo Georgia" park, and Vake cemetery provides significant ecosystem services. Annually, these green spaces sequester substantial amounts of carbon from the atmosphere (4.6 tons in "Expo Georgia" park, 4.7 tons in "Red Park," and 34.23 tons at Vake Cemetery). They store carbon in the woody tissue of trees (126.5 tons in "Red Park," 198.4 tons in "Expo Georgia" park, and 859 tons at Vake cemetery) and absorb large amounts of various pollutants and particulates from the air (CO, NO2, O3, SO2, PM2.5, and PM10)—119.6 kg in "Expo Georgia" park, 90.3 kg in "Red Park," and 961.27 kg at Vake cemetery. The study results showed that the green infrastructure of Tbilisi's urban parks and cemeteries has a substantial potential for ecosystem services, with an aggregated value exceeding USD 10 million. This underlines the importance of incorporating ecosystem services into urban planning and informing various urban policies.