Response of fungal composition and diversity to simulated nitrogen deposition and manipulation of precipitation in soils of an Inner Mongolia desert steppe of Northern China

Nitrogen (N) deposition and precipitation changes can strongly influence soil microbial properties in arid and semiarid regions. Here, we examined these effects on soil samples from the Inner Mongolia desert steppe of northern China after 7 yr of consecutive simulated N deposition by adding NH4NO3 and manipulation of precipitation, using a dilution plate method, PCR analysis, and 18S rRNA sequencing. The experimental treatments were as follows: control (CK), N addition (+N), N and water addition (+N+W), and N addition plus water reduction (+N-W). In this study, 14 genera and 32 fungal species were isolated, and Penicillium was determined to be the dominant fungal group. Treatment +N-W significantly increased (by 94.8%) the number of cultivable fungi as compared with CK. Compared with the CK community, fungal communities exposed to the three treatments, especially +N+W and +N-W, showed shifts in the relative abundances of cultivable fungi. Treatment +N-W significantly enhanced species richness compared with +N at the 0–2 cm soil depth. However, N addition and manipulation of precipitation did not influence species richness, the Shannon–Weiner index, or evenness at the 0–30 cm soil depth. This study can provide insight into how fungal composition and diversity respond to climate change scenarios.