Assessment of Terrestrial Carbon Stock: Evaluating Forest Structure and its Carbon Sequestration Potential of the Ecotone Region in Gama Luma

Abstract Forests globally store an estimated 861 gigatons of Carbon, but deforestation and forest degradation present considerable threats. Bhutan significantly contributes to global climate change efforts, prioritizing carbon sequestration through sustainable forest management. Bhutan's dedication includes maintaining at least 60% forest cover for all times to come. Therefore, such goals highlight the importance of investigating the carbon dynamics in this region. This study explores the carbon sequestration potential of the unexamined ecotone region in Gama Luma. A random sampling method was used, and a total of 30 sampling plots were laid out in 37 hectares of study area. We examined relationships between carbon stock, biomass, and variables such as DBH, Important Value Index, total tree height, basal area, diversity, and tree species density, including an overview of biomass accumulation and carbon sequestration potential across species. Field surveys identified 351 trees from 22 species and 16 families, with Myrsine capitellata and Pinus roxburghii as the dominant species. The ecotone forest region is young, with trees mostly in the 10 - 20cm DBH class. The findings showed that Castanopsis tribuloides had the highest biomass accumulation of 1.690 Mg/ha and carbon stock of 0.845 Mg C/ha, while Zanthoxylum armatum had the lowest. A positive correlation (r = 0.774, p< 0.05) between DBH distribution and carbon sequestration potential was observed. These findings highlight the ecotone region's significant carbon storage capacity and underscores the importance of its conservation and sustainable management for climate change mitigation, offering valuable insights for policymakers and forest managers in Bhutan and other regions.