An Assessment of Carbon Sequestration and Biodiversity using the Shannon-Weiner Index of Trees for Sustainable Urban Campus Management: A Case Study at Sri Lanka Technology Campus

Abstract

This study evaluates the carbon sequestration potential of tree species within the Sri Lanka Technology Campus (SLTC) to identify high-performing species and support the university's sustainability objectives. Carbon sequestration is vital for climate change mitigation, especially in semi-urban environments. The study involved a comprehensive inventory of 429 trees across 49 species. Measurements included Diameter at Breast Height (DBH), height, and biomass, followed by aboveground and belowground biomass calculations, dry weight, and carbon content. The Shannon-Weiner Index was employed to estimate biodiversity. The findings revealed that Alstonia macrophylla (Devil Tree), Mangifera indica (Mango), and Azadirachta indica (Neem) are the dominant species. However, Kigelia africana and Acacia lebbeck emerged as the most efficient species regarding carbon sequestration potential. The campus trees collectively sequestered approximately 442.9 tons of carbon. The presence of exotic species, such as Alstonia macrophylla, suggests a decline in native biodiversity, indicating the need for restoration. This research provides a framework for enhancing carbon sequestration through strategic species selection, supporting SLTC's role in climate change mitigation, and contributing to Sri Lanka's broader environmental goals. These findings also highlight the importance of regular tree monitoring and biodiversity promotion to maximize long-term carbon sequestration benefits.