Precipitation drives the biogeographic distribution of soil fungal community in Inner Mongolian temperate grasslands

Understanding the biogeographic distribution of soil fungal communities is crucial for assessing the impacts of environmental factors on terrestrial biodiversity and ecosystem functioning. Here, we investigated spatial variations of fungal communities across three different types of temperate grasslands along a transect in the Inner Mongolia, China. The aims were to understand the biogeographic patterns of fungi and key drivers shaping soil fungal communities in temperate grasslands. The composition and diversity of soil fungal community across 30 sites of the meadow steppe, typical steppe, and desert steppe along a 1200-km transect were studied through pyrosequencing. The relationships between fungal communities and environmental and biotic factors were assessed. The results showed that the fungal community along this transect exhibited strong dependence on soil moisture content and nitrate concentration, while the fungal alpha diversity was positively correlated with precipitation and below-ground biomass. Drier environment has resulted in a shift towards an Ascomycota-dominating fungal community. Our findings suggest that the distribution and community structure of soil fungal communities are primarily driven by precipitation. Plant biomass and soil nutrient status which are also influenced by precipitation are also predictors of fungal community. Our results provide important implications for understanding the linkages among environmental factors and soil fungal communities in Eurasian steppe ecosystems.