Growth and Carbon Sequestration Potential of Tbilisi City Forest Under Climate Change Conditions (South Caucasus)

Abstract

Climate change is one of the pressing issues in today’s world. Greenhouse gases play a major role in maintaining the global energy balance, but a small change in their concentration in the atmosphere can affect the Earth's climatic conditions. Carbon dioxide (CO₂) is one of the main greenhouse gases, the concentration growth of which in the atmosphere is the main cause of global warming. Urban forests have great potential to sequester carbon dioxide from the atmosphere and mitigate the impacts of climate change in urban areas, however, at the same time, they are vulnerable to climate change and anthropogenic pressure. Our study object Tbilisi city (the capital) forest is located in the area of negative impact of dangerous natural events caused by climate change, which is enhanced by the anthropogenic factor caused by growing urbanization. Rapid urbanization is considered a major driver of global change in the atmosphere, climate change, driving land use change, habitat loss, biodiversity decline, and pollution both within and outside the city. This research examined the potential of growing wood stock, living biomass, and carbon sequestration in the different forest formations of Tbilisi city forests under climate change conditions for the following years: 1964, 1874, 1984, and 2018. The study data show that the growth rate of Tbilisi city forest, respectively, accumulation ability of wood stock, biomass, and carbon stock is low, both in comparison with the corresponding data of the forests of eastern Georgia and with the corresponding data of the forests of Central-Eastern Europe. However, some forest formations, namely, Beech - is good. The mentioned data show that the forest in the surroundings of  Tbilisi cannot properly fulfill its protective function including climate change mitigating function, and it is clear that effective management measures are needed to maintain and enhance the sustainability of the study forest. To improve the conditions of Tbilisi city forest, it is necessary, on the one hand, to reduce the negative impact factors associated with rapid urbanization, and on the other hand, to activate measures to promote the natural regeneration of local woody plant species that are more adaptable to climate change.