Aboveground biomass and carbon sequestration potential of tree species in KRAEFI-Sumile Botanical and Zoological Garden

Abstract

Forest ecosystems are crucial to mitigating the effects of global warming because they function as carbon sinks and sources of carbon, regulating the flow of carbon dioxide (CO₂) in the atmosphere. This study estimated the aboveground biomass and potential of carbon sequestration of tree species within the Knights of Rizal Agricultural Endeavor Foundation, Incorporated (KRAEFI) Sumile Botanical and Zoological Garden in Butuan City, Philippines. A stratified random sampling design was employed to represent the tree population accurately. The assessment involved tree identification, diameter measurement at breast height (DBH), and the total tree height. Using an allometric equation, data from 18 plots revealed 115 individual trees representing 12 families. Among them, Swietenia macrophylla, Gmelina arborea, and Acacia mangium recorded the highest Importance Value at 180.76, 47.26, and 14.84, respectively, while Eucalyptus deglupta had the lowest at 1.77. The total aboveground biomass in the study site was 53,219.6 kg. Based on this biomass, the estimated total carbon sequestered was 86.46 Mg/ha. The study emphasized the critical influence of tree size and age on carbon sequestration potential, with older, larger trees storing more carbon. These findings are essential for guiding botanical garden management, restoration planning, and the selection of tree species with high carbon storage capacity to support climate change mitigation efforts.