Comparison of above and below ground carbon stock across a different land use type: A case of Jelo, Jelo-Muktar forest district, West Harrerge Zone, Oromiya Regional State Ermias Bekure Addis Ababa University, 2013 The present study was conducted to access the carbon stock estimation and comparison of different carbon pools (above ground, below ground, litter and soil organic carbon found in selected participatory and state managed old and young aged plantation and natural forest blocks .The biomass and carbon stock storage of each tree were determined by using quadrant plots of 10 x 20 m distributed along transect lines. Considering different variables (DBH classes, age groups.) General tropical dry forest biomass regression equation and direct laboratory result were used The studies revealed that above and below ground carbon stock of the old age natural forest blocks were 185.80 - 36.83 t ha -1, and above and below ground carbon stock of the young age natural forest blocks were 29.80 --6.55 t ha-1), respectively. Soil organic carbon stock of the old age natural forest blocks was 107.31 t ha -1 and the young age natural forest blocks were 127.5 t ha 1.Litter carbon stock of the old and the young age natural forest blocks were (3.98 t ha -1, 5.32 t ha-1), respectively. The above and belowground carbon stock per hectare were higher for the old age group but the young age forest blocks had higher Litter and soil organic carbon stock (t ha-1). While comparing with other studies, the old age natural forest block (above and below ground carbon) was larger than those estimates obtained in some countries and comparable to estimates obtained in similar environmental conditions. Concerning plantation forest blocks ,The mean above and belowground carbon stocks of the old age plantation forest blocks were (36.72 t ha-1, 7.34 t ha-1) and The mean above and belowground carbon stocks of the young age plantation forest blocks were (31.1 t ha-1, 6 t ha-1 ). Soil organic carbon stock of the young and old age plantation forest blocks were (88.86 t c ha -1; 59.45 t c ha -1), respectively The above and belowground carbon stock per hector were higher for the old age .In contrast the young age plantation forest blocks had higher soil organic carbon stock. Keywords: Biomass carbon stock, Land-use type, Carbon sequestration, Litter, Soil organic carbon