The role of plant-soil-microbe interactions on nitrogen cycling under drought and warming in grasslands

An accurate understanding of the plant-soil biogeochemical cycles is crucial to model the impacts of global change. However, further exploration is needed to disentangle the role of microbes in plant carbon and nitrogen uptake under warming and drought. In this study we perform a manipulative experiment increasing temperature and water deficit in 240 pots, considering six different grassland species (2 forbs, 2 grasses, and 2 N-fixers) and two different soil types (coming from intensive and extensive managing practices). By analyzing N content, N labeling, and biomass production in the soil, microbial, belowground, and aboveground compartments we study potential interactions between the plant-microbial-soil system in different conditions. Preliminary results indicate that water availability is more important than warming to regulate biomass production and nutrient uptake. In addition, N availability determines the interaction between plants and the microbial community. These findings will help better incorporate the role of microbes in nutrient cycling and better understand the impacts of future conditions, anticipated to be warmer and dryer.