Journal of Ornamental Horticulture

Anthropogenic emissions of carbon dioxide (CO₂) have reached critical thresholds, necessitating robust terrestrial carbon sinks to mitigate climate change. Phytosequestration-the biologically mediated capture and storage of atmospheric CO₂ by plants-has emerged as a cornerstone strategy in ecosystem-based carbon management. Urban and peri-urban landscapes, particularly institutional campuses, offer a controlled environment to evaluate the carbon sequestration potential of various tree species while simultaneously addressing their landscape functionality. This study presents a detailed, data-intensive comparative analysis of major indigenous and exotic avenue tree species based on their carbon sequestration potential and landscape utility, conducted within the Annamalai University campus, Tamil Nadu, in the year 2022. Using biometric and allometric parameters such as diameter at breast height (DBH), total tree height, fresh and dry biomass, and CO₂ conversion coefficients, this research quantifies the phytosequestration rates of five replicates per species. The selected taxa include indigenous species-Ficus religiosa (Peepal), Peltophorum pterocarpum (Rusty Copper Shield), Azadirachta indica (Neem), and Millettia pinnata (Pungam)-and exotic species-Albizia saman (Rain Tree) and Acacia auriculiformis. Results indicate that Ficus religiosa demonstrated the highest average carbon sequestration rate (0.46 kg/day/tree), significantly outperforming its exotic counterparts. Peltophorum pterocarpum and Azadirachta indica followed closely, with sequestration potentials of 0.42 and 0.25 kg/day/tree, respectively. Among exotics, Albizia saman ranked highest (0.44 kg/day/tree), while Acacia auriculiformis showed minimal sequestration capacity. Furthermore, indigenous species exhibited superior adaptability, canopy architecture, and socio-cultural value, reinforcing their preference in sustainable urban forestry programs.