ИСТИНА

Warming of the climate may inevitably greatly affect the structure and functioning of soil communities. Fungi are one of the most important groups of soil organisms. We have studied the reaction of the soil mycobiota to conditions simulating some scenarios of climate warming. In laboratory experiment with zonal (Umbric Albeluvisoil) and urban soils (Urbic Technosol, Moscow) studies were made of the structural and functional diversity of fungi at different soil temperatures (10, 20, 30°C) in the course of succession for 1 month. Functional diversity was determined by ECOLOG, the species diversity of cultivated microfungi was assessed by the isolation on the Capek medium. In field experiments with shelters studies were made on the changes of cellulolytic fungal assemblages in soils. The investigations were held with cellulose baits. Radial growth rate and sporulation of pothentially pathogenic fungus Aspegillus sydowii were measured on the solid Czapek medium at a temperature of 5-42°C and water activity of 0.99-0.80 aw. High temperature (30°C) had a negative effect on the microfungal assemblages in zonal soil, which manifested itself in a weak expression of successional stages, reduction of species and functional diversity of fungi. By contrast, for the fungal assemblages of Urbic Technosol at soil temperature (30°C) the changes of species and functional diversity have not been identified. In experiments with shelters it was shown that even short-term (monthly) changes in the course of daily temperatures can increase the diversity of cellulolytic fungi and the intensity of the colonization of cellulose. In urban soils, under shelters it was revealed that the frequency of thermotolerant species of Aspergillus (A.fumigatus, A.ochraceus, etc.), known to be potentially pathogenic for human, increased. In long-term field studies growth of abundance of these fungi in urban soils was noted in the hottest summers. On the example of species A. sydowii comparison of the properties of environmental and clinical isolates was made. Сlinical strains of A.sydowii can easily survive in soils. It has been demonstrated that the optimal temperature for the growth of clinical isolates is higher than that for environmental ones. Climate warming may affect the species, functional diversity and the growth of a number of environmental and trophic groups of soil fungi, including those hazardous to humans. The work was supported by grant 11-04-00857-а RFBR.