Estimation of land cover changes and biomass carbon stock in north-eastern hill forests of Bangladesh

Forests are atmospheric CO2 sinks, but their losses and degradation accelerate the emissions of carbon stored as a sink. Deforestation and forest degradation are widespread in Bangladesh, but their impact on greenhouse gas (GHG) emissions is unknown. We assess land use and land cover (LULC) change and forest loss in this study by classifying different Landsat satellite imagery with a focus on forest cover loss from 1989 to 2020. Tier 1 standards were used to estimate the carbon removal and emissions from a small-scale tropical forest. Over the last three decades, the forest area has decreased by 2.40%, 3.74% and 7.52%, respectively. The primary causes of forest loss are large-scale tea garden and homestead expansion, as well as increase in agricultural activities. Because of a reduction in the forest area, the annual gain of carbon in forest biomass has also decreased. Although overall carbon emission was a net gain for the Maulvibazar hill forest, it has decreased from 331.24 Gg.yr-1 in the first decade (1989 to 2000) to 307.7 Gg.yr-1 in the most recent decade (2011 to 2020), which is an alarming trend. As a result, this research will contribute to leaders' commitment to "halt and reverse forest loss and land degradation by 2030" at the 26th United Nations Climate Change Conference of the Parties (COP 26) in 2021 to improve carbon sequestration, combat climate change and conserve biodiversity.