An attempt was made to determine fire selectivity for different vegetation classes and habitat conditions using the HSI (Habitat Suitability Index) model. This is an example of expert model based on theoretical knowledge and experience of researchers. HSI analyses were originally designed to study animal habitat preferences. The assessment of inherent differences in the flammability of the selected fragments of forest stands was carried out on the basis of the derivative vector layers and raster images. The obtained results show fuel characteristics of the forest environment and the theoretical paths of fire spread preferences.