Soil organic carbon and total nitrogen predict large-scale distribution of soil fungal communities in temperate and alpine shrub ecosystems

Abstract

Soil fungi play important roles in soil organic matter decomposition, nutrient cycling processes and maintaining close associations with aboveground plant communities. However, the large-scale distribution patterns and drivers of soil fungal communities in shrub ecosystems remain largely unknown. In this study, we examined soil fungal communities among different shrub sites, and the relative importance of plant communities, abiotic factors and spatial distance in shaping the variations of soil fungal communities over large scales. Herb plant richness and diversity, shrub aboveground biomass (AGB), and soil properties showed varying differences among different sites. Soil fungal community diversity was the highest in Huangyuan and Guide, whereas the lowest in Dulan. Soil fungal community structures were significantly different among temperate and alpine grasslands. Random forest analysis showed that soil fungal α diversity was mainly predicted by soil organic carbon (SOC) and total nitrogen (TN), followed by other parameters such as AGB and mean annual precipitation. Variation partition analysis and redundancy analysis showed that shifts in shrub fungal community structures were predominantly determined by SOC and TN, followed by plant and spatial factors such as herb plant diversity, latitude and longitude. Collectively, our results suggested that incorporation of SOC and TN into Earth System Model might improve the prediction of fungal communities in terrestrial shrub ecosystems.