Forests have a role as carbon sinks and come under the spotlight when the world is facing the climate change problem. Urban forests have functions as the most effective carbon sinks. Banda Aceh City only has 7.15 ha of urban forest, and the vegetation that grows in the urban forest is essential for carbon emissions reduction. This study aimed to determine the potential tree biomass and carbon sink value in the BNI Urban Forest, Banda Aceh City, Indonesia. This study used vegetation analysis by inventory method with the census sampling method. The diameter of all trees was measured, and tree biomass, carbon stocks, and carbon sequestration were calculated. This study identified 16 tree species in the BNI Urban Forest with a total of 318 individuals, showing Casuarina equisetifolia as the most dominant tree (163 trees). The above-ground biomass, carbon stock, and carbon sequestration by the vegetation in the BNI Urban Forest were 24.66 tons/ha, 11.59 tons/ha, and 42.51 tons/ha, respectively. This study presented the vegetation conditions and the potential of carbon sequestration, which can be used to monitor and evaluate the benefits of the existence of urban forests in Banda Aceh. Keywords: carbon sequestration, carbon stock, green open space, tree biomass, urban forest

The development of the economy and the increase in population in urban areas have led to the increasing use of green open space for other purposes. The development of green open space (RTH) is expected to improve the environmental quality of an urban area and revitalize urban ecosystems. BNI City Forest has various types of trees to support the beauty and beauty of urban areas, the presence of tree species in the BNI City Forest Environment has not yet identified the location of the tree distribution, therefore research on identifying the distribution of trees in the BNI City Forest area needs to be carried out. The method used in this research is census ,namely by recording all types and numbers of trees that are above ground level. The results showed that the tree species in the BNI Banda Aceh City Forest area were 16 tree species consisting of 8 families with a total of 318 individuals, Sea cedar ( Casuarina equisetifolia ) was the most commonly found tree species, namely 163 trees (51.3% ). Trees in the BNI City Forest area need to be considered for proper maintenance so that the tree can be maintained and beautiful.Keywords: Urban Forest, tree distribution, green open space, census method