Modelling of forest carbon dynamics in different forest management scenarios: A case study on poplar and black locust plantations in Hungary

Abstract Long-term forest carbon modelling is helpful in climate change mitigation actions. Estimating potential carbon sequestration in forests can be considered the long-term strategy for low carbon and climate resilience in the National Determination Contribution. In Hungary, the black locust ( Robinia pseudoacacia ) and poplars ( Populus sp.) are prominent and dominant species in reforestation and afforestation projects. The research aimed to estimate the carbon dynamics of black locust and white poplar long rotation plantations in some forest management scenarios. Thirty-six forest management scenarios were developed from two species, six yield classes, and tree wood utilization. CO2FIX modelling projected carbon dynamics for 45 years of rotation. Our findings have shown that class yield I resulted in the highest carbon stock compared to class yields II–VI. Black locust plantations have stored carbon to a larger extent than white poplar plantations. In terms of wood utilization, harvested black locust or white poplar wood contributed the most extensive carbon stock if used for pulp. In conclusion, from 36 forest management scenarios, the best scenario was black locust plantation in class yield I and the aim for pulp that stored the carbon at the end of rotation was 101.75 Mg C/ha. In all forest management scenarios, the soil carbon stock was higher than carbon in biomass, products, and bioenergy. Thus, conserving the soil as the dominant carbon pool is vital for future policy recommendations.