2025 Reports

CO₂ Uptake by Urban Forests in Seoul and its Implications for Nature-based Solutions in Cities

Hong, Jinkyu; Lee, Keunmin; Hong, Je-Woo

Our society is steadily embracing urban green space for its role in mitigating heat waves and anthropogenic CO₂ emissions. This study reports surface fluxes of energy and CO₂ in an artificially constructed urban forest in monsoon East Asia. This study shows that the urban forest reduces both the warming trend and urban heat island intensity compared to the adjacent high-rise urban areas and that photosynthetic carbon uptake is large despite relatively small tree density and leaf area index. Further analysis reveals that ecosystem respiration in urban forests is more pronounced than for typical natural forests in a similar climate zone. This can be attributed to the substantial amount of soil organic carbon due to intensive historical use and soil transplantation during forest construction, as well as relatively warmer temperatures in urban areas. Our findings suggest the need for caution in soil management when aiming to reduce CO₂ emissions in urban areas.