Yang,F., N.Zhang, Q.Zhao, X.Luo, X.Zhou, H.Guo, Y.Zhang and S.Hu S.. 2025.
Background and Aims The seasonal coupling between plant and soil microbial nutrient utilization is vital for maintaining plant productivity in highly nutrient-limited alpine ecosystems. However, the mechanisms underlying this coupling are not fully understood and the impact of climate change on related processes and its consequences for nutrient retention remain largely unknown. Methods We investigated the temporal nitrogen (N) dynamics within the plant-soil-microbe system as influenced by two pervasive climate change drivers, warming and precipitation increase, in a Tibetan alpine meadow. Results Our results showed that the temporal coupling between plant and soil microbial N utilization occurred largely due to a N redistribution from soil microbes to plants during the growing season, highlighting the pivotal role of soil microbial biomass as a transient N reservoir when plant N demand is low. Yet, warming, precipitation increase, and their combination increased microbial N mineralization at the end of growing season, and did not lead to a corresponding increase in plant biomass N. The mismatch between N release and plant N demand suggests that increased N losses may have occurred because of the decoupling of plant and microbial N utilization to warming and precipitation increase. Conclusion These results advance our understanding of the temporal coupling of plant and microbial N utilization and its response to climate change drivers, which may help improving biogeochemical models for better predicting ecosystem N retention and productivity under future climate scenarios.
