Vilonen, Leena L. , Smith, Melinda D. , Yuan, Jing , Trivedi, Pankaj
2026-04-27 GRASS AND FORAGE SCIENCE 2026 81(卷), 2(期), (null页)
Drought is increasing in severity and duration across the United States, particularly in arid and semi-arid regions. Previous research has shown that drought has strong impacts in drier versus more mesic regions for aboveground productivity. Less research exists on belowground responses and whether they will be similar to those observed aboveground. Our study aimed to (1) measure resistance and (2) resilience of belowground responses to drought and (3) determine if these responses were uniform or differed among four grassland sites spanning a 375 to 892 mm precipitation gradient in the Central US in a 30 day greenhouse experiment. We measured several key belowground responses: inorganic nitrogen, potential extracellular enzyme activity and microbial community composition (16S/ITS). We found that the wettest grassland site (mesic tallgrass prairie) was the most sensitive to the short-term drought, showing decreases in alpha diversity for fungi, differences in beta diversity for fungi and decreases in all soil enzymes measured. This may indicate that microbial communities at wetter sites are less adapted to drought and thus exhibit stronger changes in function or composition. Post-drought, there was evidence for increased enzyme activity for most enzymes at all sites, but these differences were quickly resolved after 2 weeks, indicating high resilience to short-term drought irrespective of grassland type. This research elucidates the differential responses of belowground ecosystems to short-term drought across a precipitation gradient, highlighting the importance of understanding soil microbial dynamics for predicting ecosystem resilience in the face of increasing drought severity.