Modeling forest dynamics in a nature reserve: a case study from south-central Sweden

This paper presents a modelling study on the forest dynamics in Helgedomen Nature Reserve (HNR) in Sweden. The main components of the forest transitions that occurred between 1930 and 2010 were described. The gradual conversion of Scots pine (Pinus sylvestris L.) dominated stands into stands with a high proportion of Norway spruce (Picea abies [L.] Karst.) was observed. Next, the capabilities of the modelling system (FORKOME) in predicting the future development of forests in the reserve were tested. The model was validated by simulating forest development from 1930 to 2010, and then it was applied to project the future development of forests in the reserve. Scenarios generated in the forecasting component of the model were (1) no intervention, (2) removal of spruce, and (3) prescribed burning. The FORKOME model was able to predict possible alterations of species composition, stem volume, total biomass in the next 100 years under these three scenarios. We argue that in the absence of natural fires, the active management of small reserves is required in order to maintain the major natural values. Prescribed burning is more effective than spruce removal for maintaining the pine-dominated character of the stands and to sustain the conservation value of the reserve.