THE EFFECT OF CHANGING HYDROCLIMATE ON SOIL MICROBIAL FUNCTIONS INVOLVED IN SOIL C AND NUTRIENT CYCLING

Microbial communities play a vital role in regulating soil organic matter (SOM) decomposition by releasing diverse enzymes. However, there is still a lack of clear understanding of how microbial functional diversity responds to environmental changes, especially soil water availability, over time and the resulting impact on SOM decomposition. To address these knowledge gaps, we integrated soil hydrothermal and physiochemical properties as well as omics-based microbial functional information from multiscale observation networks to predict spatiotemporal dynamics of soil microbial functions involved in soil carbon (C) and nutrient cycles. We have utilized long-term average climate and physiochemical conditions to identify to develop a machine learning model and applied it to predict the spatial distribution of microbial functional composition involved in SOM decomposition across the continental United States (CONUS) scale. Building on this study, we further identified the temporal distribution of soil microbial function in response to current and previous drought events. Our studies indicated that soil physiochemical properties and annual climatological conditions regulated the spatial distribution of microbial functions involved in soil C and nutrient cycling, whereas the temporal dynamics of these microbial functions were strongly dominated by the current and historical drought events. Our findings provided gene-scale evidence and the predictable model to elucidate the life history strategies of soil microbial communities under changing hydroclimate.