Abstract
Trees on closed woodlands and open grazing lands play a crucial role in storing biomass carbon and soil carbon. These trees have received much attention recently due to their contribution to climate change mitigation through carbon storage.
This research study done in quantification of biomass carbon and soil carbon stocks in closed woodland and adjacent open grazing lands in Adami Tullu Jiddo Kombolcha district. Converting the biomass to biomass carbon, the carbon stock stored in different pools of closed woodland were 10.87t c/ha, 2.94t c/ha and 0.58t c/ha for the aboveground, belowground and litter respectively. Similarly, in the open grazing land 6.77t c /ha, 1.83t c/ha and 0.05t c/ha was resulted in the aboveground, belowground and litter respectively. The sum of biomass carbon from different pools ranges from 8.6 t c/ha to 14.3 t c/ha in closed woodland and open grazing. It shows significant difference at P < 0.05. In the above result, the total biomass carbon (AG, BG and LC) of closed woodland contributed more 5.74 t c/ha than open grazing land. The mean soil organic carbon of closed woodland (89.36t c/ha) was more than that of open grazing land 84.67t c/ha). The total carbon stock for ecosystem is calculated by summing the carbon stock densities of the individual carbon pools in the ecosystem. In the present study, comparing the four carbon pools, the largest carbon stock was contributed by the soil carbon pool, which accounted 92.71% in closed woodland and 90.73% in open grazing land of the four carbon pools and the second was the aboveground carbon pool which accounted for 10.48% in closed woodland and 7.25% in open grazing land of the four carbon pools. The lastly recorded was in litter carbon pool which accounted for 0.56% in closed woodland and 0.05% in open grazing land. In general, comparing the total carbon stock of the two ecosystems, closed woodland area accounts 52.45% total carbon stock as compared to open grazing land which accounted 47.35% to the ecosystem. The study investigated the effectiveness of closing woodlands help to restore aboveground, belowground and soil carbon stock in the central rift valley of ATJK, Ethiopia. The results showed that the closing and improved management practice of woodland had a significant potential to increase carbon storage. Key words : Carbon storage, Allometric equations., Estimation of carbon, Soil organic carbon.
