Modeling birch seed supply and seedling establishment during forest regeneration

- A model for predictions of naturally regenerated birch seedlings in southern Sweden have been developed.
- The model is process-based and uses national satellite-based model data and easy accessible environmental data.
- Validation shows that the model can be used as a prediction tool for practical forestry.

The seed ecology and regeneration management of birch species in Fennoscandia has been quite thoroughly investigated through decades of forestry research. Nonetheless, there are few methods for precise predictions of spontaneous natural regeneration. In this study a first framework of a model is presented that combines possible seed supply with seed emergence and seedling survival based on GIS data and the results of past experiments. The birch seed supply was calculated by combining spatial data on standing birch volume with birch seed dispersal distributions. The establishment on a site was further estimated based on the effect parameters of soil moisture conditions and soil scarification. This model shows a reduced variance compared to general means of seed supply and partly explains the variation between sites with the same soil scarification treatments. Even though additional management and ecological variables should be incorporated to increase the model's predictive ability, it could already be of use in practical forestry.