The taxonomic composition and diversity of soil fungi and bacteria living beneath coarse woody debris and in background areas of intact mesic broad-leaved forest will be evaluated by means of metagenomic analysis. The study will be conducted in the Kaluzhskie Zasieki State Nature Reserve and its buffer zone. The forests of the Reserve are unique in their multispecies composition, high age of trees, presence of single and mass windthrows located in different ecotops. Soil microorganisms, especially fungi and bacteria, largely mediate the response of forests on important challenges, including carbon dioxide, warming, drought and fire, pest outbreaks and nitrogen deposition. Nowadays we have a limited understanding of the spatial-temporal dynamics of soil microorganisms, restricting our ability to assess long-term effects of climate and land-cover change on microbial roles in soil biogeochemistry. The project involves studying the microbiome of forest soils in intact broadleaved forests with regard to natural disturbances represented by mass and single windthrows. A comparative analysis of the soil microbiome beneath deadwood and in the background soil will allow both to describe for the communities of soil fungi and bacteria of a multi-species intact broad-leaved forest, and to characterize natural changes in these communities, having clear spatial and temporal characteristics. Thus, new results, relevant for the development of world and Russian science will be obtained.
The novelty of the study is determined both by the complex nature of the proposed methods (ecology, soil science, mycology, microbiology and structural genomics) and by the uniquely broad set of research objects. For the first time, metagenomics methods will be applied to soil samples taken in different ecotopes under dead wood of eight tree species (Quercus robur, Fraxinus excelsior, Tilia cordata, Ulmus glabra, Acer platanoides, Populus tremula, Betula pendula and Picea abies) and in the background broad-leaved forest to comparatively analyze soil microdiversity. We will test hypotheses about the influence of downed trunk, its species identity on the diversity and composition of microorganisms under deadwood, as well as the original hypothesis about the influence of soil type (Podzol/Arenosol, Retisol/Luvisol and Phaozem according to WRB) in broad-leaved forests on the diversity of soil fungi and bacteria. The results will be comparable with and complementary to the results of worldwide studies of the soil microbiome in forest communities due to the originality of the object of study and the hypotheses tested.
The study of the soil microbiome beneath deadwood will complement the results obtained in the current RNF project on metabarcoding of fungal and bacterial communities in deadwood of 8 tree species at 5 stages of decomposition. Soil samples for metagenomic analysis will, if possible, be taken beneath the trunks from which wood samples were previously collected. The potential relationship between xylobiont and soil communities of fungi and bacteria will be assessed.
Research of the microbiome of forest soils, coupled with research of deadwood, is of great importance in relation to climate change, maintaining the diversity and sustainability of terrestrial ecosystems. The project will provide new results important for mitigating the effects of climate change on our planet and achieving the goals of carbon-based regulation of the economy.
