Impact of rainfall variability and grazing pressure on plant diversity in Mongolian grasslands

► We examine the vegetation response to rainfall variability and grazing pressure. ► Regional rainfall showed positive/negative relationship with grass/shrub richness. ► Rainfall variability was the determinant of species richness in desert-steppe zone. ► Species richness changed with grazing pressure in steppe zone. ► Rainfall would be more important as a cause of vegetation changes in dryer areas.