Abstract: Soils are the foundation of terrestrial ecosystems, performing functions that range from supporting agricultural industries and regulating nutrient cycles to storing most of Earth’s terrestrial carbon. Soil microorganisms and invertebrates are particularly important components of soil ecosystems, as they are the primary consumers that regulate decomposition and nutrient turnover. However, soil communities and their associated functions are at risk because of increased climatic and anthropogenic pressures acting on soil ecosystems simultaneously. We explored how interacting global stressors, including the introduction of antibiotics, increasing temperature and changing precipitation, are shaping communities and nutrient cycling in our soils. We combined field assessments of CO2 respiration, decomposition, temperature and moisture with lab-based assessments of microbial communities and function using quantitative PCR, metagenomic and metabarcoding techniques, total microbial biomass and mineralizable carbon, and soil nutrient availability. Additionally, we examined the soil invertebrate community using Berlese funnel approaches. We found that as soils experience increasing stress, their communities are disrupted and their carbon use efficiency is diminished. We also saw disruptions in the soil food web, which resulted in slower rates of decomposition. Additionally, we explored how these stressors influence the abundance of antibiotic resistance in our soil ecosystems. We found strong links between environmental characteristics like nutrient levels, temperature and precipitation and the prevalence of antibiotic resistance in soils. Combined, this work highlights the growing need to examine multiple global change factors in order to accurately characterize and predict the future of soil health and function.
