The diploma thesis deals with the influence of different levels of moisture deficit on forest tree seedlings in established experiments in regulated conditions. Prior to planting, the seedlings were treated with various determinants, the effect of which was evaluated. An experiment with beech seedlings (Fagus sylvatica, L) was established in 2018, experiment with spruce seedlings (Picea abies (L.) Karst.) was established in 2020, in both cases to observe the effect of different levels of moisture deficit. The seedlings used in both experiments were divided into control variants, variants with the commercial ectomycorreous preparation Ectovit and variants with the hydroabsorbent Agrisorb in order to compare and evaluate the positive effects of the determinants. While maintaining the same other abiotic conditions, for all sections of the experimental samples, the seedlings were stressed by varying degrees of moisture deficit. The application of Agrisorb hydrogel and mycorrhizal biopreparation Ectovit did not confirm a significant effect on any of the evaluated parameters in beech or spruce seedlings. In the survival assessment, seedlings treated vith Ectovit cinfirmed best results in both experiments with periodic irrigation and non-irrigation variant, and seedlings treated with Agrisorb confirmed highest percentage of living seedlings at the end of the experiments in the half-irrigation variant