Estimation of Organic Carbon Stock Under Soil Depth and Land Use Types of Wacho Forest, Southwest Ethiopia: An Implication for Climate Change Mitigation

Forest land is converted to different land use types through the action of human kind in Ethiopian dry Afromontane Forest in general and Wacho forest in particular. Therefore, the study was conducted to estimate organic carbon stock in relation with soil depth and land use types of Wacho forest soil, northwest Ethiopia, and its implication for climate change Mitigation. Systematic random sampling technique was used to collect the soil samples, and the soil samples were collected from each of the five 1 m × 1 m subplots situated at the four corners and one at the midpoint of 20 m × 20 m of 73 main plots. The soil organic carbon stock and the soil organic carbon CO2 equivalent were determined by standardized mathematical equations. One-way analysis of variance was used to test the effect of soil depth and land use types on organic carbon stock of Wacho forest soil. The study showed that the upper most soil profile (0–30 cm) and the lowest soil profile (60–90 cm) had the largest and the least soil organic carbon stock in all land use types of the study area, respectively. The mean organic carbon stock of all land use types within the whole depth of Wacho forest soil was estimated to be 153 ± 17.7 tone/hectare. All land use types of Wacho forest soil had the potential of mitigating 1891.55 ± 239.16 t/ha CO2 equivalents. Generally, soil depth and land use type had a statistically significant effect on organic carbon stock of Wacho forest soil at α (0.05).