Presented are the results from investigating the morphostructure of unusual forms of pine trees (Pinus sylvestris L.) and larch trees (Larix sibirica Lebed.) growing on aeolian sand forms. The present-day sand formations along the northwestern shore of Olkhon Island have been studied. The study revealed the main factors of sand environment: shifting sand, the mechanical impact of a strong wind and a dry climate of the territory which disturb the natural strategy of development of the vegetative organs in woody plants. The morphostructure of the modified individuals showed characteristic attributes indicating the pathways by which the external organs were reconstructed. It is shown that the reconstruction of the forms is based on adaptive variability of the vegetative organs permitting the individuals to retain and maintain their vitality of the organism after destruction. Ten varieties of ecological forms of the modifiers were identified according to the habitus and form of the crown. It is established that the origination of modifications implies a response to a change in growth conditions occurring in unfavorable ecological situations. The importance of the preservation of the unusual forms of woody plants in special landscape parks is outlined.Keywords: dune sands, abiotic factors, habitus, crown, modification.