EN
Different kinds of solar radiation (direct, diffuse) shape microclimate of forest gaps and have significant influence on establishment and growth of young trees. Adjustment of the shape and size of artificial gaps could create favourable conditions that meet the demands of particular species. Unfortunately there is lack of publications concerning this topic, which could be used directly for silvicultural planning in Polish conditions. Empirical assessment of radiation regimes in a wide range of different shaped gaps is impossible from practical reasons, so modelling in ArcGis environment was used instead. Gaps of different shape and size were modelled as elliptical depression in terrain by the use digital elevation model. The Solar Radiation tool was used to model direct and global radiation on the bottom of the gaps with area varying between 2 and 50 are surrounded by stands of height between 15 to 35 meters. The outcome of modelling was presented in form of nomograms. Additional series of analyses was created to describe the influence of terrain aspect and inclination on solar radiations supplies on the forest floor in gaps. Presented nomograms could be helpful in silvicultural planning, because they could be used to design artificial gaps with expected solar radiations supplies.