Ecosystem Services Provided by Urban Forests in the Southern Caucasus Region: A Modeling Study in Tbilisi, Georgia

Abstract

All cities globally are growing considerably as they are experiencing an intensive urbanization process that leads to high soil consumption and pollution of environmental components. For this reason, cities are required to adopt measures to reduce these impacts and tree planting has been suggested as a cost-effective strategy. In our study, we implemented for the first time in a Southern Caucasus city the i-Tree Eco model to quantify the main ecosystem services provided by urban forests. Trees in two parks in Tbilisi, EXPO Park (694 trees) and RED Park (1030 trees), have been measured, and a model simulation was performed for the year 2018. These green infrastructures store large amounts of carbon in their woody tissues (198.4 t for EXPO Park and 126.5 t for RED Park) and each year they sequester 4.6 and 4.7 t of CO2 for EXPO Park and RED Park. They also remove 119.6 and 90.3 kg of pollutants (CO, NO2, O3, PM2.5, SO2), and reduce water runoff of 269.5 and 200.5 m3, respectively. This analysis highlights the key role of urban forests in improving the environmental sustainability of the city of Tbilisi and provides important decision support for tree species selection in this geographic area.

Are Ecosystem Services Provided by Street Trees at Parcel Level Worthy of Attention? A Case Study of a Campus in Zhenjiang, China

“…We also found that P. orientalis had a much higher IV than species with similar abundance. This was because it had the highest average leaf area at 1257.3 m 2 , which was higher than in species in the Southern Caucasus Region [64] and in street trees in Kyoto, Japan [17]. This may be because trees in urban streets are frequently pruned, reducing their average leaf area.…”

Trees Diversity and Species with High Ecological Importance for a Resilient Urban Area: Evidence from Cotonou City (West Africa)

“…The green spaces (C), which are represented by the woodlands and urban forests, botanical gardens, interstices and cemeteries, and the peripheral zone, are mainly full of Terminalia Catappa (15), Terminalia mantally (13), Mangifera indica (6), Adonidia merrillii (2), and Borassus aethiopum. The establishments (D), which are mainly training and apprenticeship centers, are peaked by the majority of species such as At the level of the road (F), the abundance of species reveals that the species Khaya senegalensis (59) is the most abundant followed by Terminalia mantaly (40), Terminalia superba (20), Leucaena leucocephala (18), and Gliricidia sepium (8).…”

“…According to Folega et al [9] and Alpaidze et al [18], it is evident that urban nature planning, management, and development can be combined with biodiversity conservation and preservation objectives for the perpetual improvement of the living environment in a coherent urban territory. The literature reveals that little research has been conducted on the composition and structure of urban forests in urban centers in West Africa, particularly in cities with high population growth (Nero et al [17]).…”

“…The first three most abundant species define the potential regulating services offered in this land use unit of the city. The residential compartment (E) is mainly and respectively full of species such as Terminalia mantaly (19), Mangifera indica (19), Terminalia catappa (15), Polyalthia longifolia (13), and Casuarina equisetifolia (8).At the level of the road (F), the abundance of species reveals that the species Khaya senegalensis (59) is the most abundant followed by Terminalia mantaly(40), Terminalia superba (20), Leucaena leucocephala(18), and Gliricidia sepium(8).…”

Tbilisi Through Time

“…As a result, we have a city that stretches for about 33 kilometers along Mtkvari, which, in turn, increases the time spent on transportation and the demand for private cars as well. This is a big blow to the ecological condition of the city in terms of the quality of life in Tbilisi [15]. Consequently, the urban sprawl has presented in Tbilisi with negative effects, which does not make life here pleasant, although half of the country's population is concentrated in the capital.…”