Abstract

Abiot Molla, Zebene Asfaw, Tefera Mengistu and ZewgeTeklehaimanot

Trees in agroforestry systems are potential sinks of atmospheric C due to their fast growth, productivity, high and long-term biomass carbon stock. Soil under forest and agroforestry also plays a major role in global C sequestration. The potential of woody species and perennial plants in carbon sequestration under patch natural forests and enset-coffee based agroforestry (ECAF) were examined. The assessment on biomass carbon stocks was total inventory for woody stems at ≥5 cm diameter at breast height, coffee at 15cm and Enset shrub at 10 cm from aboveground. Aboveground biomass was estimated using appropriate allometric equation and convert to carbon by multiplying 0.5. SOC was sampled using “X” design at depths of 0-30 cm. Results indicated total biomass carbon stock in patch natural forests significantly (p < 0.05) higher (258.67±41.1 Mg ha-1 ) than values for ECAF (175.3±9.77 Mg ha-1 ). In SOC, the differences were; patch natural forests (76.18±3.58 Mg ha-1) > ECAF (66.79±2.73Mg ha-1 > annual crop agricultural land (38.93 ± 2.75 Mg ha-l ). In CO2 sequestration, highest estimate values were from patch natural forests (58.04%) over its lifetime followed by ECAF (41.96%). The results confirm that patch natural forests and ECAF play a major role in climate change mitigation.