Carbon Storage Dynamics and its Economic Values in Tropical Moist Afromontane Forests, South-West Ethiopia

Abstract

Abstract Forest plays an important role in the global carbon cycle by sequestering carbon dioxide and thereby mitigating climate change. In this study, an attempt has been made to investigate the effects of land use/land cover (LULC) change (1989–2017) on carbon stock and its economic values in tropical moist Afromontane forests of the Majang Forest Biosphere Reserve (MFBR), south –west Ethiopia. Systematic sampling was conducted to collect biomass and soil data from 140 plots in MFBR. The soil data were collected from grassland and farmland. InVEST modelling was employed to investigate the spatial and temporal distribution of carbon stocks. Global Voluntary Market Price (GVMP) and Tropical Economics of Ecosystems and Biodiversity (TEEB) analysis was performed to estimate economic values (EV) of carbon stock dynamics. Correlation analysis was also employed to identify the relationship between environmental and anthropogenic impacts on carbon stocks. The results indicated that the above-ground biomass and soil organic carbon stocks were higher than the other remaining carbon pools in MFBR. The total carbon stock (32.59 Mt ha–1) in 2017 was lower than 1989 (34.76 Mt ha–1). The EV of carbon stock in 2017 was lower than in 1989. Elevation, slope, and harvesting index are important environmental and disturbance factors resulting in major differences in carbon stock among study sites in MFBR. The correlation analysis for elevation showed a positive relationship with soil carbon stocks (r = 0.39) and aboveground biomass (r = 0.08), while a negative relationship was found for slope (r = –0.04) and harvesting index (r = –0.21). This calls for urgent attention to implement successful conservation and sustainable use of forest resources in biosphere reserves.