A comparative study on the carbon storage and oxygen release capacity of Swietenia macrophylla king. and Eucalyptus camaldulensis Dehn. in northwest Bangladesh

Abstract Plantation sequesters atmospheric carbon and produces oxygen through photosynthesis and stores it as a reserve. Estimating the carbon sequestration capacity of forest tree species is essential for implementing massive plantation programs in developing countries such as Bangladesh. The present study was conducted on the carbon storage and release oxygen capacity of Swietenia macrophylla and Eucalyptus camaldulensis which were planted forest tree species in the same ecological condition. Allometric equations were applied to estimate organic carbon in two species of trees. The diameter increased with increasing height and positive correlations were found in S. macrophylla and E. camaldulensis respectively (p < 0.05). The maximum carbon storage of S. macrophylla and E. camaldulensis were 17.24 kg tree⁻ ¹ year⁻ ¹ and 21.73 kg tree⁻ ¹ year⁻ ¹ at twenty years old tree respectively. The lowest carbon storage of S. macrophylla and E. camaldulensis were 5.03 and 9.24 kg tree⁻ ¹ year⁻ ¹ at five years old, respectively. There was no significant difference (df = 11; p = 0.658) found between the DBH of the two species while their DBH were significantly different among their ages (df = 11; p = 0.000). Besides, the height of these two species was significantly difference (df = 11; p = 0.002) but not significant in their ages (df = 11; p = 0.694). The height and DBH growth became slower with the increase of the age of the plantations. The biomass, carbon stock, carbon-di-oxide storage and O₂ releasing potentiality were related to each other and significantly differed from their ages (p-value varied from 0.001 to 0.023). Comparatively higher growth performances were observed in E. camaldulensis than S. macrophylla in the same environmental conditions, management and equal ages. The findings indicated that S. macrophylla and E. camaldulensis both can be selected in the massive plantation programs in this area which will contribute to large carbon storage and play a vital role in mitigating climate change.