Research Data - Drought-induced prevalence of oligotrophic microbes inhibits soil respiration in dryland plantations

We examined soil respiration (Rs) responses of two widely planted tree species (Robinia pseudoacacia [N-fixing] and Pinus tabuliformis) to 0%, 40% and 80% rainfall reduction in a dryland in Northwest China.Rainfall reduction experiments were established in December 2021 in plantations of P. tabuliformis and R. pseudoacacia. Three treatments were applied to reduce the net input of natural rainfall to the soil: ambient rainfall (control), 40% rainfall reduction, and 80% rainfall reduction, each replicated three times in plots measuring 18 m × 20 m. Soil samples were collected from the topsoil (0–10 cm) in July 2024. Within each plot, five randomly selected soil cores were sampled using a 10 cm (5 cm diameter) soil corer.Rs was measured in situ using an LI-COR 7810 infrared gas analyzer. Rs was measured monthly during the growing seasons (May–October) of 2023 and 2024. Measurements were conducted on rain-free days between 9:00 and 11:00, a period representative of daily mean Rs.