The Re-parametrization of the DAS Model Based on 2016-2021 Data of the National Forestry Database: New Results on Cutting Age Distributions

This paper presents the DAS forest model (Distributions Applied on Stands model), a forest stand-based model suitable for projecting standing volume, increment, harvest, and carbon sequestration on the stand, regional, or country levels. The forest subcompartment is the modelling unit of the DAS model, which uses National Forestry Database (NFD) data, including geospatial data. The model is suitable for further processing spatially explicit input parameters such as climate change forecasts. The model output is also georeferenced and can be further processed using GIS software. The model handles the data of approximately 600,000 forest subcompartments. Data on tree species, origin, age, growing stock, increment etc. of each subcompartment are stored in “tree-species rows”, which are the sub-units of the model. The DAS model simultaneously processes the data of 1.2 million tree species rows and describes their development in time. It uses parameters based on the actual processes of the reference period. It also uses empiric cutting age distributions and a regeneration matrix derived from historic NFD data. The ForestLab project (TKP2021-NKTA-43) is currently engaged in the re-parametrization of the model based on 2016–2021 data. This study discusses the functions of the harvesting ratio distribution in the modelling process and in determining the subcompartments selected for harvest. The paper presents the latest results regarding the 2016–2021 cutting age distributions and the preparation of the new set of species-specific and yield class-specific average harvesting ratio distributions.