Concluding Remarks
This study shows that winter warming rapidly alters fungal functional gene composition and potential fungal interactions in Alaskan tundra soil, which are closely linked to the changes of soil hydrological conditions and plant productivity. Higher fungal C degradation capacities under warming suggest positive feedback of fungal communities to a warmer climate because an increase in R ecois observed, signifying the potential importance of fungi in de-stabilizing tundra soil C storage. Although it is uncertain whether these conclusions are ubiquitous in other arctic tundra ecosystems due to the limited sampling size and small-scale spatial variability of this study, it represents an important step forward to understand the fungal functional potentials changed by warming. Overall, this study demonstrates fungal community vulnerability to climate warming and provides new insights into the fungi-mediated C storage in tundra soil. Therefore, incorporating fungi into current Earth system models may help predict the future fate of global C storage.