LAUSR

Rewetting after precipitation events plays an important role in regulating soil carbon (C) and nitrogen (N) turnover processes in arid and semiarid ecosystems. Here, we conducted a 48-h rewetting simulation experiment with measurements of soil C and N mineralization rates (RC and RN, respectively) and microbial biomass N (MBN) at high temporal resolution to explore the pulse responses of RC and RN. RC and RN responded strongly and rapidly to rewetting over the short term. The maximum RC value (because of pulse effects) ranged from 16.53 to 19.33 µg C gsoil−1 h−1, observed 10 min after rewetting. The maximum RN varied from 22.86 to 40.87 µg N gsoil−1 h−1, appearing 5–6 h after rewetting. The responses of soil microbial growth to rewetting were rapid, and the maximum MBN was observed 2–3 h after rewetting. Unexpectedly, there was no correlation between RC, RN, and MBN during the process of rewetting, and RC and RN were uncoupled. In sum, the pulse responses of RC, RN, and microbial growth to simulated rewetting were rapid, strong, and asynchronous, which offers insights into the different responses of microbes to rewetting and mechanisms behind microbes.