Effects of nitrogen fertilization on carbon accumulation in boreal forests: Model computations compared with the results of long-term fertilization experiments

Computations with a gap-type forest simulation model indicate that net primary production increased by 20% in a mesic site and 44% in a dry site due to an increased nitrogen input of 600–750 kg N/ha over a 26- to 30-year period. In addition to enhanced carbon sequestration by the vegetation, the nitrogen input increased carbon storage in the litter and humus layers. The results of these model computations were similar to those of the long-term field experiments. Thus, it can be assumed that the model can be used for assessing the effect of nitrogen input on the biomass production and carbon balance of forest ecosystems.