The study of the processes of adaptation of fungi belonging to the microbocenosis of forest litter is important in terms of improving the enabling environment for coniferous species seedlings in forest nurseries. On the one hand, the fungi are involved in the cooperative action of microbocenosis during decomposition of pesticides and their residual amounts accumulated from agricultural activities. On the other hand – the successful adaptation of fungi in the rhizosphere will create favorable conditions for the growth of seedlings. The study of changes in the number of fungi in three field experiments have shown that the ability to more successfully to adapt in the soil of the forest nursery fungi complexes of forest litter taken from birch and mixed stands.